--- a/www/js/global.js	Fri Apr 17 11:29:37 2020 +0200
+++ b/www/js/global.js	Sat Apr 18 11:12:28 2020 +0200
@@ -1062,6 +1062,14 @@
 
 
 
+function calc_svg(og, fg) {
+ var oe = sg_to_plato(og);
+ var ae = sg_to_plato(fg);
+ return (oe - ae) / oe * 100;
+}
+
+
+
 function brix_to_sg(brix) {
  if (my_brix_correction > 0)
   return plato_to_sg(brix / my_brix_correction);