diff --git a/docs/layout/widths/index.html b/docs/layout/widths/index.html
index b1fa2a30c..23d7b084b 100644
--- a/docs/layout/widths/index.html
+++ b/docs/layout/widths/index.html
@@ -142,7 +142,7 @@ <h3 class="f6 ttu tracked mt0">Widths</h3>
   -100 = literal value 100%
 
   -third  = calc(100% / 3)
-  -two-thirds  = calc(100% / 3)
+  -two-thirds  = calc(100% / 1.5)
   -auto  = string value auto