diff -r cd1403633e96 -r bcc4583fd013 www/js/global.js
--- a/www/js/global.js	Sun Dec 09 22:27:38 2018 +0100
+++ b/www/js/global.js	Mon Dec 10 22:20:19 2018 +0100
@@ -235,6 +235,36 @@
 }
 
 
+
+function estimate_fg(percSugar, percCara, WGratio, TotTme, Temp, attenuation, og) {
+
+	var	BD;
+
+	console.log("estimate_fg("+percSugar+","+percCara+","+WGratio+","+TotTme+","+Temp+","+attenuation+","+og+")");
+
+	if (percSugar > 40)
+		percSugar = 0;
+	if (percCara > 50)
+		percCara = 0;
+	if ((WGratio > 0) && (TotTme > 0)) {
+		BD = WGratio;
+		BD = max(2, min(5.5, BD));
+		Temp = max(60, min(72, Temp));
+	} else {
+		BD = 3.5;
+		Temp = 67;
+		TotTme = 75;
+	}
+	if (attenuation < 30)
+		attenuation = 77;
+
+	var AttBeer = 0.00825 * attenuation + 0.00817 * BD - 0.00684 * Temp + 0.00026 * TotTme - 0.00356 * percCara + 0.00553 * percSugar + 0.547;
+	var fg = Math.round((1 + (1 - AttBeer) * (og - 1)) * 1000) / 1000;
+	console.log("fg:"+fg);
+	return fg;
+}
+
+
 /*
  * Steinie:
  *