This calculator is really awesome, I've only got a few suggestions for improvement: ABV calculation: When priming with wort of the same OG as the rest of the batch, this feature won't really be necessary, however, when priming with wort of different OG/FG, or when adding sugar as well, it'd be neat if the calculator would calculate what the final ABV of the brew would be. It'd be neat to add a choice next to "Gyle FG" (when inputting gyle of different OG/FG) for "Use same attenuation" which will be useful when using gyle from the same mash, that's been either reduced, or if the rest of the batch except the gyle has been diluted before pitching. Secondly, I'd suggest addressing an ambiguity in this calculator; "Volume being packed" - does that refer to the total amount including the priming wort, or without? It'd probably be nice making a visual illustration at the end of the calculator displaying the results for example like this: 25 liters of beer + 2.5 liters of gyle with a certain OG/FG + 50 grams of sugar = 27.5 liters of beer ready for priming which will be this or that ABV with this or that CO2 content That way, I think the calculator would be easier to understand. Anyway, thanks for a fantastic tool which I've only recently discovered and which I'll probably use a lot!