diff --git a/layouts/shortcodes/splice/calc_loop.html b/layouts/shortcodes/splice/calc_loop.html
index dd9f83c..76f9f83 100644
--- a/layouts/shortcodes/splice/calc_loop.html
+++ b/layouts/shortcodes/splice/calc_loop.html
@@ -22,7 +22,7 @@ function Calculate(obj)
     obj.length_extended.value = length_extended.toFixed(1) +"cm";
 }
 </script>
-<form>
+<form onsubmit="return false;">
     <div class="form-group">
         <label for="line_diameter">Line diameter</label>
         <select class="form-control form-control-lg" name="line_diameter" onChange="Calculate(this.form)">