diff -r 97c237654ddd -r b43214d218c0 www/includes/formulas.php
--- a/www/includes/formulas.php	Mon Feb 04 20:56:44 2019 +0100
+++ b/www/includes/formulas.php	Tue Feb 05 21:55:22 2019 +0100
@@ -1,6 +1,9 @@
 <?php
 
 define('EURO', chr(128));
+define('DEG', chr(176));
+
+define('SUGARDENSITY', '1.611');
 
 define('MMCa', '40.048');
 define('MMMg', '24.305');
@@ -266,6 +269,15 @@
 
 
 
+function kettle_cm($vol, $kettle_vol, $kettle_height) {
+
+	if (($vol > 0) && ($kettle_vol > 0) && ($vol <= $kettle_vol))
+		return 100 * ((1 - $vol / $kettle_vol) * $kettle_height);
+	return 0;
+}
+
+
+
 /*
 
 Brouwhulp data.pas