diff --git a/docker/build-calculator.sh b/docker/build-calculator.sh
new file mode 100755
index 0000000..4c549f7
--- /dev/null
+++ b/docker/build-calculator.sh
@@ -0,0 +1,90 @@
+#!/bin/bash
+# Build KiCad PCB Calculator WASM inside Docker, then apply asyncify on host.
+# Mirrors docker/build.sh; differences:
+#   - calls scripts/kicad/build-calculator.sh inside the container
+#   - copies pcb_calculator.* from build-wasm/kicad-calculator and renames to
+#     calculator.* on the host (keeps the kicad-fork patch minimal)
+#   - runs host-side passes against output/calculator.{js,wasm}
+
+# Redirect all output to a log file (re-execs script with redirection)
+source "$(dirname "$0")/../scripts/common/logging.sh"
+
+set -e
+
+cd "$(dirname "$0")/.."
+
+# Use branch name as Docker Compose project name for isolated containers/volumes
+BRANCH_NAME=$(git rev-parse --abbrev-ref HEAD | tr '/' '-' | tr '[:upper:]' '[:lower:]')
+export COMPOSE_PROJECT_NAME="kicad-wasm-${BRANCH_NAME}"
+echo "Using Docker project: ${COMPOSE_PROJECT_NAME}"
+
+# Add -j 10 by default if no -j flag is given
+ARGS=("$@")
+if [[ ! " ${ARGS[*]} " =~ " -j " ]]; then
+    ARGS+=("-j" "10")
+fi
+
+# Start container if not running
+docker compose -f docker/docker-compose.yml up -d
+
+# Sync source code to container volume (same flake-tolerant retry as build.sh).
+echo "Syncing source code to container..."
+sync_rc=0
+for sync_attempt in 1 2 3; do
+    if docker compose -f docker/docker-compose.yml exec kicad-wasm-builder \
+        rsync -r --delete --checksum --inplace \
+            --exclude="build-wasm" \
+            --exclude="output" \
+            --exclude=".git" \
+            --exclude="logs" \
+            --exclude=".idea" \
+            --exclude="node_modules" \
+            --exclude="tools/emsdk" \
+            /workspace-host/ /workspace/
+    then
+        sync_rc=0
+    else
+        sync_rc=$?
+    fi
+    { [ $sync_rc -eq 0 ] || [ $sync_rc -eq 24 ]; } && break
+    echo "rsync attempt ${sync_attempt} failed (exit ${sync_rc}); retrying in 2s..."
+    sleep 2
+done
+if [ $sync_rc -ne 0 ] && [ $sync_rc -ne 24 ]; then
+    echo "ERROR: source sync failed after retries (exit ${sync_rc})"; exit 1
+fi
+
+# Run build inside container.
+docker compose -f docker/docker-compose.yml exec -e EMSDK=/emsdk kicad-wasm-builder \
+    /workspace/scripts/kicad/build-calculator.sh "${ARGS[@]}"
+
+# Copy outputs. Artifacts are named calculator.* directly thanks to the
+# OUTPUT_NAME calculator property we set on the pcb_calculator target for
+# EMSCRIPTEN builds (kicad/pcb_calculator/CMakeLists.txt).
+echo "Copying build output to ./output/..."
+docker compose -f docker/docker-compose.yml exec kicad-wasm-builder \
+    bash -c '
+        set -e
+        mkdir -p /workspace/output
+        SRC=/workspace/build-wasm/kicad-calculator/pcb_calculator
+        cp "$SRC/calculator.js"   /workspace/output/calculator.js
+        cp "$SRC/calculator.wasm" /workspace/output/calculator.wasm
+        [ -f "$SRC/calculator.worker.js" ]        && cp "$SRC/calculator.worker.js"        /workspace/output/calculator.worker.js        || true
+        [ -f "$SRC/calculator.wasm.map" ]         && cp "$SRC/calculator.wasm.map"         /workspace/output/calculator.wasm.map         || true
+        [ -f "$SRC/calculator.wasm.debug.wasm" ]  && cp "$SRC/calculator.wasm.debug.wasm"  /workspace/output/calculator.wasm.debug.wasm  || true
+        cp /workspace/build-wasm/kicad-calculator/resources/images.tar.gz /workspace/output/images.tar.gz 2>/dev/null || true
+        cp /workspace/build-wasm/wxwidgets/build/wasm/wx.js               /workspace/output/wx.js          2>/dev/null || true
+    '
+
+# Inject dynCall shims into the JS loader (fixes Emscripten 4.x dynCall_* errors).
+./scripts/common/inject-dyncall-shims.sh output/calculator.js
+
+# Run wasm-emscripten-finalize on host (memory-intensive, skipped inside Docker).
+./scripts/common/apply-finalize.sh output/calculator.wasm output/calculator.wasm
+
+# Run wasm-opt --asyncify on host (~20-30GB RAM).
+./scripts/common/apply-asyncify.sh output/calculator.wasm output/calculator.wasm
+
+echo ""
+echo "Build complete. Output files in ./output/"
+ls -lh output/
diff --git a/docker/build.sh b/docker/build.sh
index 290112a..d466557 100755
--- a/docker/build.sh
+++ b/docker/build.sh
@@ -33,20 +33,40 @@ docker compose -f docker/docker-compose.yml up -d
 # This avoids the timestamp mismatch cycle that caused full rebuilds every time.
 # Transferred files get current container time, so make detects them correctly.
 echo "Syncing source code to container..."
-# rsync exit code 24 = "some files vanished before transfer" (harmless race condition)
-docker compose -f docker/docker-compose.yml exec kicad-wasm-builder \
-    rsync -r --delete --checksum \
-        --exclude="build-wasm" \
-        --exclude="output" \
-        --exclude=".git" \
-        --exclude="logs" \
-        --exclude=".idea" \
-        --exclude="node_modules" \
-        --exclude="tools/emsdk" \
-        /workspace-host/ /workspace/ || [ $? -eq 24 ]
+# rsync into the macOS-backed volume intermittently hits transient VirtioFS glitches:
+# temp-file rename failures (exit 23) or vanished-source files (exit 24, harmless).
+# --inplace avoids the temp-file+rename pattern that triggers exit 23; retry up to 3x
+# for any residual flakiness (--checksum makes each retry skip already-synced files).
+sync_rc=0
+for sync_attempt in 1 2 3; do
+    if docker compose -f docker/docker-compose.yml exec kicad-wasm-builder \
+        rsync -r --delete --checksum --inplace \
+            --exclude="build-wasm" \
+            --exclude="output" \
+            --exclude=".git" \
+            --exclude="logs" \
+            --exclude=".idea" \
+            --exclude="node_modules" \
+            --exclude="tools/emsdk" \
+            /workspace-host/ /workspace/
+    then
+        sync_rc=0
+    else
+        sync_rc=$?
+    fi
+    { [ $sync_rc -eq 0 ] || [ $sync_rc -eq 24 ]; } && break
+    echo "rsync attempt ${sync_attempt} failed (exit ${sync_rc}); retrying in 2s..."
+    sleep 2
+done
+if [ $sync_rc -ne 0 ] && [ $sync_rc -ne 24 ]; then
+    echo "ERROR: source sync failed after retries (exit ${sync_rc})"; exit 1
+fi
 
 # Run build command (without asyncify - handled on host due to memory requirements)
-docker compose -f docker/docker-compose.yml exec kicad-wasm-builder \
+# -e EMSDK=/emsdk: `docker compose exec` bypasses the entrypoint that sources
+# emsdk_env.sh, so the build shell would lack emcc/embuilder on PATH. Setting
+# EMSDK lets scripts/common/env.sh source /emsdk/emsdk_env.sh and activate the toolchain.
+docker compose -f docker/docker-compose.yml exec -e EMSDK=/emsdk kicad-wasm-builder \
     /workspace/scripts/kicad/build-pcbnew.sh "${ARGS[@]}"
 
 # Copy output to host-accessible directory
diff --git a/kicad b/kicad
index 6efc02a..0cc6362 160000
--- a/kicad
+++ b/kicad
@@ -1 +1 @@
-Subproject commit 6efc02aacfc876323e0bef14425fb7c7ae56eea5
+Subproject commit 0cc6362377080b06e7ef662ba25f1e8ccccfd8bc
diff --git a/scripts/kicad/build-calculator.sh b/scripts/kicad/build-calculator.sh
new file mode 100755
index 0000000..1f15996
--- /dev/null
+++ b/scripts/kicad/build-calculator.sh
@@ -0,0 +1,305 @@
+#!/bin/bash
+# Build KiCad PCB Calculator for WebAssembly.
+# This builds the standalone pcb_calculator app as a single WASM binary.
+#
+# Mirrors scripts/kicad/build-pcbnew.sh almost verbatim; differences:
+#   - separate build tree: build-wasm/kicad-calculator
+#   - no pcbnew_scripting_stub (calculator doesn't link scripting)
+#   - embind compiles wasm/bindings/calculator_embind.cpp
+#   - final make target is `pcb_calculator` (single binary, no kiface MODULE,
+#     enabled by the EMSCRIPTEN branch we added to pcb_calculator/CMakeLists.txt)
+#
+# Usage:
+#   ./scripts/kicad/build-calculator.sh [options]
+#
+# Options (same as build-pcbnew.sh):
+#   --full        Full clean rebuild (dependencies + KiCad)
+#   --clean-kicad Clean only KiCad-calculator build directory (not deps)
+#   --build-deps  Build dependencies (default: skip)
+#   --debug       Build with debug symbols (default)
+#   --release     Build optimized without debug symbols
+#   -j N          Parallel compilation jobs (default: 1)
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "${SCRIPT_DIR}/../common/env.sh"
+source "${SCRIPT_DIR}/../common/versions.sh"
+source "${SCRIPT_DIR}/../common/functions.sh"
+
+KICAD_DIR="${PROJECT_ROOT}/kicad"
+KICAD_BUILD="${BUILD_ROOT}/kicad-calculator"
+KICAD_STAMP="${BUILD_ROOT}/stamps/kicad-calculator.stamp"
+WASM_LAYER="${PROJECT_ROOT}/wasm"
+WX_BUILD="${BUILD_ROOT}/wxwidgets-universal"
+
+# Parse arguments - incremental build by default (optimized for development)
+NO_CLEAN=1
+FULL_CLEAN=0
+SKIP_DEPS=1
+DEBUG=0
+DIAG_LIST=""
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        --full)
+            FULL_CLEAN=1
+            NO_CLEAN=0
+            SKIP_DEPS=0
+            shift
+            ;;
+        --clean-kicad)
+            NO_CLEAN=0
+            shift
+            ;;
+        --build-deps)
+            SKIP_DEPS=0
+            shift
+            ;;
+        --debug)
+            DEBUG=1
+            shift
+            ;;
+        --release)
+            DEBUG_BUILD=0
+            export DEBUG_BUILD
+            shift
+            ;;
+        --diag=*)
+            DIAG_LIST="${1#--diag=}"
+            shift
+            ;;
+        --diag)
+            DIAG_LIST="$2"
+            shift 2
+            ;;
+        -j)
+            export JOBS="$2"
+            shift 2
+            ;;
+        -j*)
+            export JOBS="${1#-j}"
+            shift
+            ;;
+        *)
+            shift
+            ;;
+    esac
+done
+
+# Diagnostic preprocessor defines (same as build-pcbnew.sh)
+DIAG_DEFINES=""
+if [ -n "${DIAG_LIST}" ]; then
+    IFS=',' read -ra _diag_cats <<< "${DIAG_LIST}"
+    for _cat in "${_diag_cats[@]}"; do
+        case "${_cat}" in
+            gal)       DIAG_DEFINES="${DIAG_DEFINES} -DKICAD_DIAG_GAL=1" ;;
+            coroutine) DIAG_DEFINES="${DIAG_DEFINES} -DKICAD_DIAG_COROUTINE=1" ;;
+            ctor)      DIAG_DEFINES="${DIAG_DEFINES} -DKICAD_DIAG_CTOR=1" ;;
+            all)       DIAG_DEFINES="${DIAG_DEFINES} -DKICAD_DIAG_GAL=1 -DKICAD_DIAG_COROUTINE=1 -DKICAD_DIAG_CTOR=1" ;;
+            "")        ;;
+            *)         log_warn "Unknown --diag category: '${_cat}' (valid: gal, coroutine, ctor, all)" ;;
+        esac
+    done
+    log_info "Diagnostic logging enabled:${DIAG_DEFINES}"
+fi
+
+log_info "Using ${JOBS} parallel jobs"
+
+# Step 1: Clean build directories
+if [ $FULL_CLEAN -eq 1 ]; then
+    log_info "Full clean: removing all stamps and build directories..."
+    rm -rf "${STAMPS_DIR}"/*
+    rm -rf "${BUILD_ROOT}/deps"/*
+    rm -rf "${BUILD_ROOT}/wxwidgets-universal"
+    rm -rf "${BUILD_ROOT}/stubs"
+    rm -rf "${KICAD_BUILD}"
+    rm -rf "${SYSROOT}"/*
+elif [ $NO_CLEAN -eq 0 ]; then
+    log_info "Cleaning KiCad Calculator build directory..."
+    rm -rf "${KICAD_BUILD}" "${KICAD_STAMP}"
+else
+    log_info "Incremental build (use --clean-kicad or --full to clean)"
+fi
+
+# Step 2: Build dependencies (shared sysroot with pcbnew)
+if [ $SKIP_DEPS -eq 0 ]; then
+    log_info "Building dependencies..."
+    "${SCRIPT_DIR}/../deps/build-all-deps.sh" --with-occ
+else
+    log_info "Skipping dependencies (use --build-deps or --full to build)"
+fi
+
+# Step 4: Build wxWidgets (shared with pcbnew)
+log_info "Building wxWidgets..."
+"${SCRIPT_DIR}/../build-wxuniversal-wasm.sh" --no-clean
+
+log_info "Building KiCad PCB Calculator ${KICAD_VERSION} for WASM..."
+
+# Step 5: Set build type (same flags as pcbnew)
+if [ "${DEBUG_BUILD:-0}" = "1" ] || [ $DEBUG -eq 1 ]; then
+    BUILD_TYPE="Debug"
+    EXTRA_FLAGS="-g -O1 -fexceptions -matomics -mbulk-memory"
+    LINKER_DEBUG_FLAGS="-O1 -g -gseparate-dwarf -fexceptions"
+    log_info "Building Calculator in DEBUG mode (separate DWARF for smaller main binary)"
+else
+    BUILD_TYPE="Release"
+    EXTRA_FLAGS="-O2 -fexceptions -matomics -mbulk-memory"
+    LINKER_DEBUG_FLAGS="-O0 -fexceptions"
+    log_info "Building Calculator in RELEASE mode (skipping wasm-opt due to memory limits)"
+fi
+
+# Step 6: Create build directory
+mkdir -p "${KICAD_BUILD}"
+cd "${KICAD_BUILD}"
+
+# Step 6.1: Build stub libraries the calculator links against.
+# pcbnew_scripting_stub is omitted — calculator doesn't link scripting.
+STUBS_DIR="${PROJECT_ROOT}/wasm/stubs"
+STUBS_BUILD="${BUILD_ROOT}/stubs"
+mkdir -p "${STUBS_BUILD}"
+
+log_info "Building stub libraries..."
+# libgit2 stub: single_top.cpp calls git_libgit2_init / git_libgit2_shutdown.
+emcc -c "${STUBS_DIR}/libgit2_stub.c" -o "${STUBS_BUILD}/libgit2_stub.o"
+emar rcs "${STUBS_BUILD}/libgit2_stub.a" "${STUBS_BUILD}/libgit2_stub.o"
+
+# curl stub: referenced by common/.
+emcc -c "${STUBS_DIR}/curl_stub.c" -o "${STUBS_BUILD}/curl_stub.o"
+emar rcs "${STUBS_BUILD}/libcurl_stub.a" "${STUBS_BUILD}/curl_stub.o"
+
+# NNG stub: required because KICAD_IPC_API=ON. Sockets don't work in WASM.
+emcc -c -I"${STUBS_DIR}" "${STUBS_DIR}/nng_stub.c" -o "${STUBS_BUILD}/nng_stub.o"
+emar rcs "${STUBS_BUILD}/libnng_stub.a" "${STUBS_BUILD}/nng_stub.o"
+
+log_info "Stub libraries built"
+
+# Step 6.2: Swap EMSDK wasm-opt for stub (real one runs on host post-build).
+if [ -z "${EMSDK}" ]; then
+    log_error "EMSDK environment variable is not set."
+    exit 1
+fi
+EMSDK_WASM_OPT="${EMSDK}/upstream/bin/wasm-opt"
+if [ -f "${EMSDK_WASM_OPT}" ] && [ ! -f "${EMSDK_WASM_OPT}.real" ]; then
+    log_info "Backing up real wasm-opt..."
+    mv "${EMSDK_WASM_OPT}" "${EMSDK_WASM_OPT}.real"
+fi
+cp "${STUBS_DIR}/wasm-opt-stub.sh" "${EMSDK_WASM_OPT}"
+chmod +x "${EMSDK_WASM_OPT}"
+log_info "wasm-opt stub installed (asyncify will run on host)"
+
+# Step 6.3: Swap wasm-emscripten-finalize for stub (real one runs on host).
+EMSDK_FINALIZE="${EMSDK}/upstream/bin/wasm-emscripten-finalize"
+if [ -f "${EMSDK_FINALIZE}" ] && [ ! -f "${EMSDK_FINALIZE}.real" ]; then
+    log_info "Backing up real wasm-emscripten-finalize..."
+    mv "${EMSDK_FINALIZE}" "${EMSDK_FINALIZE}.real"
+fi
+cp "${STUBS_DIR}/wasm-emscripten-finalize-stub.sh" "${EMSDK_FINALIZE}"
+chmod +x "${EMSDK_FINALIZE}"
+log_info "wasm-emscripten-finalize stub installed (finalize will run on host)"
+
+# Step 6.5: Verify WASM support is in KiCad fork
+KICAD_CMAKE="${KICAD_DIR}/CMakeLists.txt"
+if ! grep -q "msw|qt|gtk|osx|wasm" "${KICAD_CMAKE}"; then
+    log_error "KiCad fork is missing WASM port detection support."
+    log_error "Please ensure the kicad submodule has WASM modifications."
+    exit 1
+fi
+KIPLATFORM_CMAKE="${KICAD_DIR}/libs/kiplatform/CMakeLists.txt"
+if ! grep -q "KICAD_WX_PORT STREQUAL wasm" "${KIPLATFORM_CMAKE}"; then
+    log_error "KiCad fork is missing kiplatform WASM support."
+    log_error "Please ensure the kicad submodule has WASM modifications."
+    exit 1
+fi
+log_info "KiCad WASM support verified"
+
+# Step 7: Configure with CMake
+log_info "Configuring KiCad Calculator with CMake..."
+
+CCACHE_OPTS=""
+if command -v ccache &> /dev/null; then
+    CCACHE_OPTS="-DCMAKE_C_COMPILER_LAUNCHER=ccache -DCMAKE_CXX_COMPILER_LAUNCHER=ccache"
+    log_info "Using ccache for compilation"
+fi
+
+emcmake cmake "${KICAD_DIR}" \
+    ${CCACHE_OPTS} \
+    -DCMAKE_BUILD_TYPE=${BUILD_TYPE} \
+    -DCMAKE_INSTALL_PREFIX="${SYSROOT}" \
+    -DCMAKE_MODULE_PATH="${WASM_LAYER}/cmake" \
+    -DSYSROOT="${SYSROOT}" \
+    -DCMAKE_POLICY_VERSION_MINIMUM=3.5 \
+    -DCMAKE_CXX_FLAGS="${EXTRA_FLAGS} -pthread -sUSE_ZLIB=1 -DKICAD_USE_PLATFORM_WASM=1${DIAG_DEFINES} -I${SYSROOT}/include -I${STUBS_DIR}" \
+    -DCMAKE_C_FLAGS="${EXTRA_FLAGS} -pthread -sUSE_ZLIB=1 -I${SYSROOT}/include -I${STUBS_DIR}" \
+    -DCMAKE_EXE_LINKER_FLAGS="${LINKER_DEBUG_FLAGS} -pthread -sUSE_ZLIB=1 -sASYNCIFY=1 -sDYNCALLS=1 -sASYNCIFY_STACK_SIZE=65536 -sUSE_PTHREADS=1 -sPTHREAD_POOL_SIZE='navigator.hardwareConcurrency' -sPTHREAD_POOL_SIZE_STRICT=0 -sALLOW_MEMORY_GROWTH=1 -sINITIAL_MEMORY=256MB -sMAXIMUM_MEMORY=4GB -sMAX_WEBGL_VERSION=2 -sEXPORTED_RUNTIME_METHODS=['ccall','cwrap','UTF8ToString','stringToUTF8','lengthBytesUTF8','dynCall'] -sDEFAULT_LIBRARY_FUNCS_TO_INCLUDE=['\$dynCall'] --bind -L${SYSROOT}/lib ${STUBS_BUILD}/libgit2_stub.a ${STUBS_BUILD}/libcurl_stub.a ${STUBS_BUILD}/libnng_stub.a ${STUBS_BUILD}/calculator_embind.o" \
+    -DCMAKE_PREFIX_PATH="${SYSROOT};${WX_BUILD}" \
+    -DwxWidgets_CONFIG_EXECUTABLE="${WX_BUILD}/wx-config" \
+    \
+    -DKICAD_BUILD_QA_TESTS=OFF \
+    -DKICAD_SPICE=OFF \
+    -DKICAD_USE_EGL=OFF \
+    -DKICAD_USE_BUNDLED_GLEW=ON \
+    -DKICAD_BUILD_3D_VIEWER_WASM=OFF \
+    -DKICAD_IPC_API=ON \
+    \
+    -DZSTD_ROOT="${SYSROOT}" \
+    -DZSTD_INCLUDE_DIR="${SYSROOT}/include" \
+    -DZSTD_LIBRARY="${SYSROOT}/lib/libzstd.a" \
+    -DGLM_INCLUDE_DIR="${SYSROOT}/include" \
+    -DGLM_VERSION="0.9.9.8" \
+    -DBOOST_ROOT="${SYSROOT}" \
+    -DBoost_INCLUDE_DIR="${SYSROOT}/include" \
+    -DBoost_LIBRARY_DIR="${SYSROOT}/lib" \
+    -DBoost_NO_SYSTEM_PATHS=ON \
+    -DBoost_NO_BOOST_CMAKE=ON \
+    -DFREETYPE_INCLUDE_DIR_ft2build="${SYSROOT}/include/freetype2" \
+    -DFREETYPE_INCLUDE_DIR_freetype2="${SYSROOT}/include/freetype2" \
+    -DFREETYPE_LIBRARY="${SYSROOT}/lib/libfreetype.a" \
+    -DHarfBuzz_INCLUDE_DIR="${SYSROOT}/include/harfbuzz" \
+    -DHarfBuzz_LIBRARY="${SYSROOT}/lib/libharfbuzz.a" \
+    -DOCC_INCLUDE_DIR="${SYSROOT}/include/opencascade" \
+    -DOCC_LIBRARY_DIR="${SYSROOT}/lib" \
+    -DProtobuf_INCLUDE_DIR="${SYSROOT}/include" \
+    -DProtobuf_LIBRARY="${SYSROOT}/lib/libprotobuf.a" \
+    -DProtobuf_LITE_LIBRARY="${SYSROOT}/lib/libprotobuf-lite.a" \
+    -DProtobuf_PROTOC_EXECUTABLE="${SYSROOT}/bin/protoc" \
+    -DODBC_CONFIG:STRING="stub-for-wasm" \
+    -DODBCLIB:STRING="" \
+    -DODBC_CFLAGS:STRING="" \
+    -DODBC_LINK_FLAGS:STRING="" \
+    -DODBC_LIBRARIES:STRING="" \
+    \
+    -DBUILD_GITHUB_PLUGIN=OFF \
+    -DKICAD_PCM=OFF \
+    \
+    -DHAVE_STRCASECMP=1 \
+    -DHAVE_STRNCASECMP=1
+
+# Step 7.1: Compile Embind bindings (after CMake so config.h exists).
+EMBIND_SRC="${PROJECT_ROOT}/wasm/bindings/calculator_embind.cpp"
+if [ -f "$EMBIND_SRC" ]; then
+    log_info "Compiling Embind bindings..."
+    WX_CXXFLAGS=$("${WX_BUILD}/wx-config" --cxxflags 2>/dev/null || echo "-I${WX_BUILD}/lib/wx/include/emscripten-unicode-static-3.2 -I${PROJECT_ROOT}/wxwidgets/include")
+    KICAD_INCLUDES="-I${KICAD_BUILD} -I${KICAD_DIR}/include -I${KICAD_DIR}/pcb_calculator -I${KICAD_DIR}/common"
+    KICAD_INCLUDES+=" -I${KICAD_DIR}/libs/core/include -I${KICAD_DIR}/libs/kimath/include -I${KICAD_DIR}/libs/kiplatform/include"
+    KICAD_INCLUDES+=" -I${KICAD_DIR}/thirdparty/clipper2/Clipper2Lib/include"
+    KICAD_INCLUDES+=" -I${KICAD_DIR}/thirdparty/nlohmann_json"
+    KICAD_INCLUDES+=" -I${KICAD_DIR}/thirdparty/dynamic_bitset"
+    KICAD_INCLUDES+=" -I${KICAD_DIR}/thirdparty/nanodbc"
+    KICAD_INCLUDES+=" -I${KICAD_DIR}/thirdparty/picosha2"
+    KICAD_INCLUDES+=" -I${KICAD_DIR}/thirdparty"
+    KICAD_INCLUDES+=" -I${SYSROOT}/include"
+    em++ -std=c++20 -c ${EXTRA_FLAGS} ${WX_CXXFLAGS} ${KICAD_INCLUDES} "$EMBIND_SRC" -o "${STUBS_BUILD}/calculator_embind.o"
+fi
+
+# Step 8: Build pcb_calculator target (single-binary WASM executable)
+log_info "Building pcb_calculator..."
+emmake make -j${JOBS} pcb_calculator
+
+# Step 8.1: Build bitmap resources (images.tar.gz)
+log_info "Building bitmap resources..."
+emmake make bitmap_archive_build
+
+# Step 9: Create stamp file
+create_stamp "${KICAD_STAMP}"
+log_info "KiCad Calculator build complete!"
+log_info "Output: ${KICAD_BUILD}/pcb_calculator/pcb_calculator.js"
diff --git a/tests/apps/kicad/calculator.html b/tests/apps/kicad/calculator.html
new file mode 100644
index 0000000..ab970cc
--- /dev/null
+++ b/tests/apps/kicad/calculator.html
@@ -0,0 +1,198 @@
+<!DOCTYPE html>
+<html lang="en-us">
+<head>
+  <meta charset="utf-8">
+  <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+  <title>KiCad Calculator WASM</title>
+  <style>
+    .emscripten { padding-right: 0; margin-left: auto; margin-right: auto; display: block; }
+    div.emscripten { text-align: center; }
+    /* the canvas *must not* have any border or padding, or mouse coords will be wrong */
+    canvas.emscripten { border: 0px none; }
+
+    .window {
+      position: absolute;
+      pointer-events: none;
+      z-index: 10;
+      background-color: black;
+      overflow: hidden;
+      width: 0;
+      height: 0;
+    }
+
+    .window-canvas {
+      position: absolute;
+      top: 0;
+      left: 0;
+      pointer-events: none;
+    }
+
+    #status {
+      position: fixed;
+      bottom: 10px;
+      left: 10px;
+      color: #fff;
+      font-family: monospace;
+      z-index: 1000;
+      background: rgba(0,0,0,0.7);
+      padding: 10px;
+      border-radius: 5px;
+    }
+
+    #progress {
+      width: 300px;
+      height: 20px;
+      background: #333;
+      margin-top: 5px;
+    }
+
+    #progress-bar {
+      height: 100%;
+      background: #4CAF50;
+      width: 0%;
+      transition: width 0.3s;
+    }
+  </style>
+</head>
+<body style="margin: 0; padding: 0; width: 100%; height: 100%; overflow: hidden; background: #1a1a2e;">
+  <div id="main-window" style="width: 100vw; height: 100vh; position: absolute; top: 0; left: 0;"></div>
+
+  <div id="status">
+    <div id="status-text">Initializing...</div>
+    <div id="progress"><div id="progress-bar"></div></div>
+  </div>
+
+  <div id="window-container"></div>
+
+  <script>
+    var mainWindow = document.getElementById('main-window');
+    var statusText = document.getElementById('status-text');
+    var progressBar = document.getElementById('progress-bar');
+
+    var showError = function(msg) {
+      console.error('[KICAD_ERROR] ' + msg);
+      statusText.textContent = 'Error: ' + msg;
+      statusText.style.color = 'red';
+    };
+
+    var createCanvas = function() {
+      var canvas = document.createElement('canvas');
+      canvas.id = 'canvas';
+      canvas.style.display = 'none';
+      // wx.js owns the backing-store size via setWindowRect(); keep the HTML
+      // shell responsible only for the CSS size.
+      var width = window.innerWidth;
+      var height = window.innerHeight;
+      canvas.style.width = width + 'px';
+      canvas.style.height = height + 'px';
+      canvas.oncontextmenu = function() { event.preventDefault(); };
+      canvas.addEventListener("webglcontextlost", function(e) {
+        showError('WebGL context lost. You will need to reload the page.');
+        e.preventDefault();
+      }, false);
+
+      mainWindow.appendChild(canvas);
+      Module.canvas = canvas;
+
+      console.log('[KICAD] preRun complete, canvas created: ' + width + 'x' + height);
+    };
+
+    var onRuntimeInitialized = function() {
+      console.log('[KICAD] Runtime initialized');
+      var canvas = Module.canvas;
+      canvas.style.display = 'block';
+      document.getElementById('status').style.display = 'none';
+    };
+
+    // Pre-fetched resource data (fetched before calculator.js loads)
+    var resourceData = null;
+
+    // Start fetching images.tar.gz immediately (runs in parallel with WASM loading)
+    fetch('images.tar.gz')
+      .then(function(response) {
+        if (!response.ok) throw new Error('HTTP ' + response.status);
+        return response.arrayBuffer();
+      })
+      .then(function(buffer) {
+        resourceData = new Uint8Array(buffer);
+        console.log('[KICAD] Prefetched images.tar.gz (' + resourceData.length + ' bytes)');
+      })
+      .catch(function(err) {
+        console.warn('[KICAD] Could not prefetch images.tar.gz:', err.message);
+      });
+
+    // Write pre-fetched resources to FS (called in preRun after FS is available)
+    var writeResources = function() {
+      // Create directory structure matching KiCad's compiled-in KICAD_DATA path.
+      // This path is baked in during CMake configuration and is shared with the
+      // pcbnew build (both use the same sysroot).
+      var resourcePath = '/workspace/build-wasm/sysroot/share/kicad/resources';
+      FS.mkdirTree(resourcePath);
+
+      if (resourceData) {
+        FS.writeFile(resourcePath + '/images.tar.gz', resourceData);
+        console.log('[KICAD] Wrote images.tar.gz to ' + resourcePath);
+      } else {
+        console.warn('[KICAD] images.tar.gz not ready yet (WASM loaded faster than fetch)');
+      }
+    };
+
+    var Module = {
+      thisProgram: '/usr/bin/pcb_calculator',  // argv[0]
+
+      preRun: [createCanvas, writeResources],
+      postRun: [],
+
+      print: function(text) {
+        if (arguments.length > 1)
+          text = Array.prototype.slice.call(arguments).join(' ');
+        console.log('[KICAD_OUT] ' + text);
+      },
+
+      printErr: function(text) {
+        if (arguments.length > 1)
+          text = Array.prototype.slice.call(arguments).join(' ');
+        console.error('[KICAD_ERR] ' + text);
+      },
+
+      setStatus: function(text) {
+        console.log('[KICAD_STATUS] ' + text);
+        statusText.textContent = text;
+
+        var match = text.match(/(\d+)\/(\d+)/);
+        if (match) {
+          var pct = (parseInt(match[1]) / parseInt(match[2])) * 100;
+          progressBar.style.width = pct + '%';
+        }
+      },
+
+      totalDependencies: 0,
+      monitorRunDependencies: function(left) {
+        this.totalDependencies = Math.max(this.totalDependencies, left);
+        Module.setStatus(left ? 'Preparing... (' + (this.totalDependencies-left) + '/' + this.totalDependencies + ')' : 'All downloads complete.');
+      },
+
+      onRuntimeInitialized: onRuntimeInitialized,
+
+      // Required for locating .wasm and .worker.js files
+      locateFile: function(path) {
+        return path;
+      }
+    };
+
+    Module.setStatus('Downloading...');
+
+    window.onerror = function(msg, url, line) {
+      showError(msg + ' at ' + url + ':' + line);
+      Module.setStatus = function(text) {
+        if (text) Module.printErr('[post-exception status] ' + text);
+      };
+      return false;
+    };
+  </script>
+
+  <!-- wxWidgets WASM glue code (defines getConfigEntryLength, etc.) -->
+  <script src="wx.js"></script>
+  <script async src="calculator.js"></script>
+</body>
+</html>
diff --git a/tests/kicad/calculator.spec.ts b/tests/kicad/calculator.spec.ts
new file mode 100644
index 0000000..bf134b4
--- /dev/null
+++ b/tests/kicad/calculator.spec.ts
@@ -0,0 +1,150 @@
+import type { Page } from '@playwright/test';
+import { test, expect } from './fixtures';
+import { clickByLabel, clickTreeItem, findAllTreeItems } from '../e2e/utils/element-tracker';
+
+/**
+ * PCB Calculator WASM E2E Tests
+ *
+ * The calculator is a wxFrame containing a wxTreebook with ~14 calculator
+ * panels grouped under four section pages. There's no GAL canvas, no
+ * toolbars-as-tested, and no setup wizard for the calculator itself.
+ *
+ * However, KiCad's first-run setup wizard pops up before *any* app's frame
+ * (same wizard pcbnew sees) because Emscripten's MEMFS starts empty each
+ * page load and KiCad finds no config. We click through it the same way
+ * pcbnew.spec.ts's completeWizard() does, then verify:
+ *   1. The calculator frame loads and registers its panels.
+ *   2. The treebook contains the panel labels we expect.
+ *   3. Clicking a leaf panel ("Color Code") switches the active page.
+ *
+ * Panel labels are sourced from pcb_calculator_frame.cpp:170-192 (kicad fork).
+ */
+
+async function waitForRegistry(page: Page): Promise<void> {
+    await page.waitForFunction(() => !!(window as any).wxElementRegistry, null, { timeout: 90000 });
+    // Give the C++ side a moment to register every panel after the frame
+    // first appears — the treebook is populated synchronously in the frame
+    // ctor, but wxElementRegistry registrations are flushed on idle.
+    await page.waitForTimeout(2000);
+}
+
+/**
+ * Click through KiCad's first-run setup wizard. Mirrors the intent of
+ * tests/kicad/pcbnew.spec.ts's completeWizard() but waits actively for each
+ * "Next >" / "Finish" button to appear in wxElementRegistry before clicking
+ * — the calculator boots quickly enough that the wizard buttons can lag
+ * behind by a second or two, and a fixed sleep proved flaky.
+ */
+async function waitForLabel(page: Page, label: string, timeoutMs: number): Promise<boolean> {
+    try {
+        await page.waitForFunction(
+            (l) => {
+                const r = (window as any).wxElementRegistry;
+                return !!(r && r.findByLabel && r.findByLabel(l, {}).length > 0);
+            },
+            label,
+            { timeout: timeoutMs }
+        );
+        return true;
+    } catch {
+        return false;
+    }
+}
+
+async function completeFirstRunWizard(page: Page): Promise<void> {
+    // The canvas becomes visible only after Module.onRuntimeInitialized fires,
+    // which is a reliable witness that the WASM has booted.
+    await expect(page.locator('#canvas')).toBeVisible({ timeout: 90000 });
+    await waitForRegistry(page);
+
+    for (let i = 1; i <= 12; i++) {
+        const haveNext = await waitForLabel(page, 'Next >', 15000);
+        if (haveNext) {
+            const clickedNext = await clickByLabel(page, 'Next >');
+            if (clickedNext) {
+                await page.waitForTimeout(400);
+                continue;
+            }
+        }
+        const haveFinish = await waitForLabel(page, 'Finish', 5000);
+        if (haveFinish) {
+            await clickByLabel(page, 'Finish');
+            await page.waitForTimeout(400);
+        }
+        break;
+    }
+
+    // Allow the wizard to dismiss and the calculator frame to register.
+    await page.waitForTimeout(2500);
+}
+
+async function getRegistryLabels(page: Page): Promise<string[]> {
+    return await page.evaluate(() => {
+        const registry = (window as any).wxElementRegistry;
+        if (!registry || !registry.findAll) return [];
+        const all = registry.findAll({});
+        return all
+            .map((el: any) => (el && el.label ? String(el.label) : ''))
+            .filter((l: string) => l.length > 0);
+    });
+}
+
+test.describe('PCB Calculator WASM', () => {
+    test.beforeEach(async ({ page }) => {
+        await page.goto('/kicad/calculator.html');
+    });
+
+    test('loads calculator frame', async ({ page, testLogger }) => {
+        void testLogger;
+        await completeFirstRunWizard(page);
+
+        // The default panel (Regulator) renders its controls into the registry
+        // as soon as the frame is up. "Calculate" is a unique button label on
+        // panel_regulator and a reliable witness that the calculator is live.
+        const labels = await getRegistryLabels(page);
+        const hasRegulatorPanel = labels.some(l => l === 'Calculate');
+        expect(hasRegulatorPanel, `expected the calculator's default Regulator panel to be live (Calculate button registered). Got: ${JSON.stringify(labels.slice(0, 30))}`).toBe(true);
+
+        await page.screenshot({ path: 'test-results/calculator-loaded.png', scale: 'device' });
+    });
+
+    test('treebook lists expected panels', async ({ page, testLogger }) => {
+        void testLogger;
+        await completeFirstRunWizard(page);
+
+        const treeItems = await findAllTreeItems(page);
+        const treeLabels = treeItems.map(i => i.label).filter((l): l is string => typeof l === 'string');
+
+        const requiredSubset = [
+            'Regulators',
+            'Resistor Calculator',
+            'Via Size',
+            'Track Width',
+            'Color Code',
+            'RF Attenuators',
+            'Transmission Lines',
+        ];
+        const missing = requiredSubset.filter(req => !treeLabels.includes(req));
+        expect(missing, `treebook is missing expected panels: ${JSON.stringify(missing)} (tree items: ${JSON.stringify(treeLabels)})`).toEqual([]);
+    });
+
+    test('switch to Color Code panel', async ({ page, testLogger }) => {
+        void testLogger;
+        await completeFirstRunWizard(page);
+
+        await page.screenshot({ path: 'test-results/calculator-before-switch.png', scale: 'device' });
+
+        const clicked = await clickTreeItem(page, 'Color Code');
+        expect(clicked, 'expected to find and click the Color Code tree item').toBe(true);
+
+        // Allow the panel to swap in. The Color Code panel exposes a unique
+        // "Tolerance" label that the Regulator panel does not — use it as a
+        // proof-of-switch.
+        await page.waitForTimeout(800);
+        const labelsAfter = await getRegistryLabels(page);
+        const onColorCodePanel = labelsAfter.some(l => /Tolerance/i.test(l));
+        expect(onColorCodePanel, `expected Color Code panel to be active after click; labels: ${JSON.stringify(labelsAfter.slice(0, 40))}`).toBe(true);
+
+        await page.screenshot({ path: 'test-results/calculator-color-code.png', scale: 'device' });
+    });
+});
diff --git a/tests/package.json b/tests/package.json
index 28601d0..68f6e55 100644
--- a/tests/package.json
+++ b/tests/package.json
@@ -13,6 +13,11 @@
     "test:kicad:chrome": "npm run setup:kicad && playwright test --config=playwright-kicad.config.ts --project=chromium --headed",
     "test:kicad": "npm run test:kicad:firefox",
     "test:kicad:headed": "npm run test:kicad:chrome",
+    "setup:calculator": "./scripts/setup-calculator-wasm.sh",
+    "test:calculator:firefox": "npm run setup:calculator && playwright test --config=playwright-calculator.config.ts --project=firefox",
+    "test:calculator:chrome": "npm run setup:calculator && playwright test --config=playwright-calculator.config.ts --project=chromium --headed",
+    "test:calculator": "npm run test:calculator:firefox",
+    "test:calculator:headed": "npm run test:calculator:chrome",
     "test:coroutine:firefox": "playwright test --config=playwright-coroutine.config.ts --project=firefox",
     "test:coroutine:chrome": "playwright test --config=playwright-coroutine.config.ts --project=chromium --headed"
   },
diff --git a/tests/playwright-calculator.config.ts b/tests/playwright-calculator.config.ts
new file mode 100644
index 0000000..911dabb
--- /dev/null
+++ b/tests/playwright-calculator.config.ts
@@ -0,0 +1,90 @@
+import { defineConfig, devices } from '@playwright/test';
+import { execSync } from 'child_process';
+import * as fs from 'fs';
+import * as path from 'path';
+
+// Mirrors playwright-kicad.config.ts. The only structural difference is
+// testMatch — calculator.spec.ts lives next to pcbnew.spec.ts under ./kicad,
+// and we filter to it so running `npm run test:calculator` doesn't drag in
+// the pcbnew suite.
+
+const PORT_FILE = path.join(__dirname, '.test-port');
+
+// NOTE: Chrome headless crashes on ARM Mac due to SwiftShader WebGL bug
+// (Chromium issues #1416283, #338414704). Firefox headless works reliably.
+// Use --project=firefox for headless, --project=chromium for headed debugging.
+
+function getOrFindPort(): number {
+  try {
+    const stat = fs.statSync(PORT_FILE);
+    const age = Date.now() - stat.mtimeMs;
+    if (age < 60000) {
+      const port = parseInt(fs.readFileSync(PORT_FILE, 'utf-8').trim());
+      if (port > 0 && port < 65536) {
+        return port;
+      }
+    }
+  } catch {
+    // File doesn't exist or can't be read
+  }
+
+  const port = findFreePort();
+  fs.writeFileSync(PORT_FILE, port.toString());
+  return port;
+}
+
+function findFreePort(): number {
+  try {
+    const result = execSync(
+      'python3 -c "import socket; s=socket.socket(); s.bind((\'\',0)); print(s.getsockname()[1]); s.close()"',
+      { encoding: 'utf-8' }
+    );
+    return parseInt(result.trim());
+  } catch {
+    return 9000 + Math.floor(Math.random() * 1000);
+  }
+}
+
+const port = getOrFindPort();
+
+export default defineConfig({
+  globalSetup: './global-setup.ts',
+  testDir: './kicad',
+  testMatch: 'calculator.spec.ts',
+  fullyParallel: true,
+  forbidOnly: !!process.env.CI,
+  retries: process.env.CI ? 2 : 0,
+  workers: process.env.CI ? 1 : undefined,
+  reporter: 'html',
+  timeout: 180000,  // KiCad WASM needs more time to load (3 minutes)
+
+  use: {
+    baseURL: `http://localhost:${port}`,
+    trace: 'retain-on-failure',
+    screenshot: 'only-on-failure',
+  },
+
+  projects: [
+    {
+      name: 'firefox',
+      use: {
+        ...devices['Desktop Firefox'],
+        viewport: { width: 1280, height: 720 },
+      },
+    },
+    {
+      // Uses system Chrome (not bundled Chromium) so WebGL runs on the real GPU.
+      name: 'chromium',
+      use: {
+        channel: 'chrome',
+        viewport: { width: 1280, height: 720 },
+      },
+    },
+  ],
+
+  webServer: {
+    command: `npx serve apps -p ${port} -c ../serve.json`,
+    port: port,
+    reuseExistingServer: !process.env.CI,
+  },
+});
diff --git a/tests/scripts/setup-calculator-wasm.sh b/tests/scripts/setup-calculator-wasm.sh
new file mode 100755
index 0000000..2ca30d8
--- /dev/null
+++ b/tests/scripts/setup-calculator-wasm.sh
@@ -0,0 +1,58 @@
+#!/bin/bash
+# Copy PCB Calculator WASM build output to the test directory.
+# Mirrors setup-kicad-wasm.sh; differences:
+#   - copies calculator.{js,wasm,wasm.map,worker.js} instead of pcbnew.*
+#
+# Priority: use local output/ (populated by docker/build-calculator.sh).
+# Fallback: copy from the Docker volume directly.
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+PROJECT_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"
+KICAD_TEST="$PROJECT_ROOT/tests/apps/kicad"
+OUTPUT_DIR="$PROJECT_ROOT/output"
+
+mkdir -p "$KICAD_TEST"
+
+if [ -f "$OUTPUT_DIR/calculator.js" ] && [ -f "$OUTPUT_DIR/calculator.wasm" ]; then
+    echo "Copying Calculator WASM files from output directory..."
+    cp "$OUTPUT_DIR/calculator.js" "$KICAD_TEST/"
+    cp "$OUTPUT_DIR/calculator.wasm" "$KICAD_TEST/"
+    # Source map for debug symbols (optional)
+    cp "$OUTPUT_DIR/calculator.wasm.map" "$KICAD_TEST/" 2>/dev/null || true
+    # Worker file for pthreads (optional)
+    cp "$OUTPUT_DIR/calculator.worker.js" "$KICAD_TEST/" 2>/dev/null || true
+    # Bitmap resources for KiCad icons (shared with pcbnew; optional)
+    cp "$OUTPUT_DIR/images.tar.gz" "$KICAD_TEST/" 2>/dev/null || true
+else
+    echo "Output directory not found, copying from Docker build..."
+    SRC=/workspace/build-wasm/kicad-calculator/pcb_calculator
+    docker compose -f "$PROJECT_ROOT/docker/docker-compose.yml" cp \
+      "kicad-wasm-builder:${SRC}/pcb_calculator.js" "$KICAD_TEST/calculator.js"
+    docker compose -f "$PROJECT_ROOT/docker/docker-compose.yml" cp \
+      "kicad-wasm-builder:${SRC}/pcb_calculator.wasm" "$KICAD_TEST/calculator.wasm"
+    # Optional artifacts (best-effort).
+    docker compose -f "$PROJECT_ROOT/docker/docker-compose.yml" cp \
+      "kicad-wasm-builder:${SRC}/pcb_calculator.wasm.map" "$KICAD_TEST/calculator.wasm.map" 2>/dev/null || true
+    docker compose -f "$PROJECT_ROOT/docker/docker-compose.yml" cp \
+      "kicad-wasm-builder:${SRC}/pcb_calculator.worker.js" "$KICAD_TEST/calculator.worker.js" 2>/dev/null || true
+    docker compose -f "$PROJECT_ROOT/docker/docker-compose.yml" cp \
+      kicad-wasm-builder:/workspace/build-wasm/kicad-calculator/resources/images.tar.gz "$KICAD_TEST/" 2>/dev/null || true
+fi
+
+# wxWidgets WASM glue code (shared with pcbnew).
+echo "Copying wxWidgets WASM glue code..."
+if [ -f "$OUTPUT_DIR/wx.js" ]; then
+    cp "$OUTPUT_DIR/wx.js" "$KICAD_TEST/"
+else
+    if docker compose -f "$PROJECT_ROOT/docker/docker-compose.yml" cp \
+      kicad-wasm-builder:/workspace/build-wasm/wxwidgets/build/wasm/wx.js "$KICAD_TEST/" 2>/dev/null; then
+        :
+    else
+        cp "$PROJECT_ROOT/wxwidgets/build/wasm/wx.js" "$KICAD_TEST/"
+    fi
+fi
+
+echo "Calculator WASM files copied to $KICAD_TEST"
+ls -lh "$KICAD_TEST"
diff --git a/wasm/bindings/calculator_embind.cpp b/wasm/bindings/calculator_embind.cpp
new file mode 100644
index 0000000..9810154
--- /dev/null
+++ b/wasm/bindings/calculator_embind.cpp
@@ -0,0 +1,18 @@
+/*
+ * Embind bindings for KiCad PCB Calculator WASM.
+ *
+ * Currently empty — reserved for future calculator-specific JS bindings
+ * (e.g., exposing transmission-line calculators or attenuator math to
+ * Pyodide / browser callers). Kept as a separate translation unit so the
+ * calculator build pipeline mirrors pcbnew's pcbnew_embind.cpp structure.
+ */
+
+#ifdef __EMSCRIPTEN__
+#include <emscripten/bind.h>
+
+using namespace emscripten;
+
+EMSCRIPTEN_BINDINGS(pcb_calculator) {
+    // Reserved for future calculator-specific JS bindings.
+}
+#endif
diff --git a/wxwidgets b/wxwidgets
index d1d1627..6fb2eac 160000
--- a/wxwidgets
+++ b/wxwidgets
@@ -1 +1 @@
-Subproject commit d1d1627b279672fc71deb4ff4512a7771dfc2cc8
+Subproject commit 6fb2eac2572cf0d3964ba8bec8d73e017d311733