Homebrewing calculators
Gravity, alcohol, bitterness and carbonation — each one showing the formula it used and citing where that formula comes from, so you can check the answer instead of trusting it.
Gravity & Alcohol
- ABV CalculatorAlcohol by volume from original and final gravity, with both the standard and the high-gravity formula side by side, plus Brix and Plato input.
- Brix to Specific Gravity ConverterConvert between Brix, degrees Plato and specific gravity in both directions, using the published conversion polynomials, with a reference table.
- Attenuation CalculatorApparent attenuation from original and final gravity: how much of the sugar your yeast actually ate, and what typical strains reach.
- Gravity Dilution CalculatorWater to add to hit a target gravity, the gravity after dilution, and the result of blending two volumes, by mass balance on gravity points.
Hops & Bitterness
Packaging & Carbonation
Where the numbers come from
Brewing calculators disagree with each other more than you would expect, because several of the formulas in common use are empirical fits rather than derivations, and different tools quietly pick different ones. The ABV pages here show two formulas side by side for exactly that reason — at ordinary strengths they agree, and at high gravity they part by nearly a percent.
Where a formula's source could not be retrieved, the calculator is simply not here. That is why there is no Rager bitterness model — its gravity adjustment is published but its utilisation table is not — and no mash or strike water calculator, since the canonical reference for it is currently unreachable. Each page says which sources it used and when they were retrieved.