diff -r 7f1d0abe5571 -r 0a39cbdcf085 www/includes/formulas.php
--- a/www/includes/formulas.php	Sun Nov 11 23:15:46 2018 +0100
+++ b/www/includes/formulas.php	Mon Nov 12 11:32:16 2018 +0100
@@ -163,12 +163,19 @@
 
 	$AttBeer = 0.00825 * $attenuation + 0.00817 * $BD - 0.00684 * $Temp + 0.00026 * $TotTme - 0.00356 * $percCara + 0.00553 * $percSugar + 0.547;
 	$fg = 1 + (1 - $AttBeer) * ($og - 1);
-//	echo $percSugar.' '.$percCara.' '.$attenuation.' attn '.$AttBeer.'  FG '.$fg.PHP_EOL;
 	return $fg;
 }
 
 
 
+function abvol($og, $fg) {
+	if ((4.749804 - $fg) <> 0)
+		return 486.8693 * ($og - $fg) / (4.749804 - $fg);
+	return 0;
+}
+
+
+
 /*
 
 Brouwhulp data.pas