Calculators
Home Brewing Calculators
Sixteen brewing calculators covering gravity, bitterness, mash water, carbonation, yeast, water chemistry and cost. Every one shows its formula and names whether that formula is a published standard or a brewing convention.
Where a calculation cannot be answered honestly, the calculator returns no answer rather than a plausible looking number.
These cover the arithmetic a brew day actually forces on you. Each one is built on the same formula library, so the answers are consistent with every reference page on this site.
All 16 calculators
ABV Calculator
Both published ABV formulas, side by side, with the gap between them shown rather than hidden.
IBU Calculator
Tinseth and Rager, both labelled, because they disagree by a predictable margin.
Strike Water Temperature Calculator
The published strike equation, with tun loss kept separate because it is not part of it.
Mash and Sparge Water Calculator
Strike, sparge and total water, with absorption and boil-off flagged as the conventions they are.
Grain Bill Calculator
Target gravity to pounds of malt, with efficiency flagged as the assumption it is.
Brewhouse Efficiency Calculator
Stop assuming an efficiency figure and measure the one your system really gives.
Hydrometer Temperature Correction Calculator
A hydrometer is calibrated at one temperature. A reading taken warm is simply wrong until corrected.
Refractometer Correction Calculator
Alcohol refracts differently from sugar, so a raw Brix reading after fermentation is wrong. This corrects it.
Priming Sugar Calculator
Corn sugar, table sugar or dry malt extract, with residual CO2 taken from the beer temperature.
Keg Carbonation Calculator
Set it, leave the gas connected, and the beer reaches equilibrium and stays there.
Yeast Pitch Rate and Starter Calculator
Pitch rates are convention, not standard. This calculator says so on the page.
Dilution and Blending Calculator
For when the wort came out stronger than the recipe intended.
Boil-Off and Evaporation Rate Calculator
The one number that makes every other volume calculation on this site accurate for your system.
Water Chemistry Salt Addition Calculator
Ion contributions follow from the chemistry. What they taste like is a different kind of claim.
Beer Colour Calculator (SRM and EBC)
Malt colour units to SRM by the published Morey fit, with its limits stated.
Cost Per Batch and Per Pint Calculator
The number that decides whether the expensive system was worth it.
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Frequently asked questions
- Why does this site show the formula on every calculator?
- Because a calculator that hides its working cannot be checked, and brewing figures get copied between sites until nobody knows where they came from. Every calculator here prints the equation it used and names whether that equation is a published standard or a widely repeated convention, so you can verify the number rather than trust it.
- What happens when a calculator cannot answer?
- It says so and shows nothing. If an input falls outside the range a published formula covers, or the numbers contradict each other, such as a final gravity higher than the original, the calculator returns no answer instead of a plausible looking one. A wrong number is far more damaging than a missing one.
- Which brewing calculations actually matter most?
- Gravity and volume drive nearly everything else. Get strike water and mash volumes right and your gravity lands where you planned, which in turn fixes ABV, bitterness balance and yeast pitch. Carbonation matters separately, because both bottle conditioning and kegging can go wrong in ways that are unpleasant or genuinely unsafe.
- Do the calculators agree with the reference pages?
- Yes, by construction. Every calculator and every generated reference page on this site calls the same formula library, so a figure worked out in your browser and the same figure baked into a static page cannot drift apart. That is deliberate, because the usual cause of contradictory brewing numbers is two different implementations.
Researched from published brewing formulas, manufacturer specifications and verified owner reviews. This is general guidance, not professional advice.