diff -r 606b4af8f918 -r d341f0a91a91 www/includes/formulas.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/www/includes/formulas.php	Sun Aug 12 21:24:33 2018 +0200
@@ -0,0 +1,22 @@
+<?php
+
+
+function ebc_to_srm($ebc)
+{
+	// Srm = -1.32303E-12*Ebc4-0.00000000291515*Ebc3+0.00000818515*Ebc2+0.372038*Ebc+0.596351
+	return  -1.32303E-12 * pow($ebc, 4) - 0.00000000291515 * pow($ebc, 3) + 0.00000818515 * pow($ebc, 2) + 0.372038 * $ebc + 0.596351;
+	//  return $ebc * 0.508;
+}
+
+
+function srm_to_ebc($srm)
+{
+	// EBC = 0.000000000176506*Srm4+ 0.000000154529*Srm3-0.000159428*Srm2+2.68837*Srm-1.6004
+	//
+	// Formule van Adrie Otten. brouwhulp.
+	$ebc = 0.000000000176506 * pow($srm, 4) + 0.000000154529 * pow($srm, 3) - 0.000159428 * pow($srm, 2) + 2.68837 * $srm - 1.6004;
+	return round($ebc);
+}
+
+
+?>