diff --git a/sppa/calc/index.html b/sppa/calc/index.html
index f9c8d178..a749198b 100644
--- a/sppa/calc/index.html
+++ b/sppa/calc/index.html
@@ -6,7 +6,7 @@
   <title>calc</title>
   <style>
     input[type="button"] {
-      width: 50px;
+      width: 60px;
       height: 50px;
       font-size: 20px;
     }