diff --git a/web/kiri/index.html b/web/kiri/index.html
index 9f4289e9..b38e4073 100644
--- a/web/kiri/index.html
+++ b/web/kiri/index.html
@@ -568,7 +568,7 @@
                         <div class="f-row var-row" title="flute diameter in inches&#010;unless metric is checked&#010;then in millimeters"><label>diameter</label><input id="tool-fdiam" size="7"></input></div>
                         <div class="f-row var-row" title="flute length in inches&#010;unless metric is checked&#010;then in millimeters"><label>length</label><input id="tool-flen" size="7"></input></div>
                         <div class="set-header f-col" ln="td_tapr">taper</div>
-                        <div class="f-row var-row" title="taper angle"><label>angle</label><input id="tool-tangle" size=7></input></div>
+                        <div class="f-row var-row" title="taper angle is measured from the center of the tool"><label>angle</label><input id="tool-tangle" size=7></input></div>
                         <div class="f-row var-row" title="tip width in inches&#010;unless metric is checked&#010;then in millimeters"><label>tip</label><input id="tool-ttip" size="7"></input></div>
                     </div>
                     <div id="tool-view" class="f-col t-33 t-body"></div>