Homebrewer's Recipe Calculator
Add your malts and hops and see how strong, bitter, and dark your beer will be - updated live as you type. Compare your recipe to recognised style categories and map your brew day with visual charts. Everything runs in your browser, nothing uploaded.
Recipe breakdown
Grain Bill Breakdown
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Hop Schedule
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BJCP Style Match
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Learn more: the formulas behind your recipe numbers
Original gravity from grain potential
The calculator turns each grain's weight in pounds into gravity points by multiplying by its potential (PPG, points per pound per gallon) and your mash efficiency, adds them up and divides by the batch volume in gallons. OG is 1 plus those points divided by 1,000.
Take 5 kg of a grain at 37 PPG in a 20 liter batch. At 72% efficiency the OG is 1.056, and at 85% it is 1.066. Efficiency alone moves the beer by 10 points, so enter the figure your own system reaches. Final gravity is OG minus the attenuation you choose, and ABV is (OG - FG) x 131.25, so 1.056 to 1.012 gives 5.8%.
IBU with the Tinseth formula
Bitterness uses Glenn Tinseth's formula. Utilization is a gravity factor, 1.65 x 0.000125^(OG - 1), times a time factor, (1 - e^(-0.04 x minutes)) / 4.15. The IBU from an addition is ounces times alpha acid times utilization times 7,489, divided by batch gallons. Dry hops with no boil time add nothing.
For 28 g of 12% alpha acid hops in 20 liters at an OG of 1.056, a 60 minute addition gives 36.7 IBU. A 90 minute addition gives 39.4, only 7% more, while a 5 minute addition gives 7.3. The formula uses your final OG as the boil gravity and does not adjust for pellets or whole leaf, so treat the number as an estimate.
Color with the Morey equation
Color comes from malt color units: each grain's pounds times its color rating divided by batch gallons. SRM is 1.4922 x MCU^0.6859. In 20 liters, 4.5 kg of 2 row (2 SRM) with 0.5 kg of Crystal 60 (60 SRM) comes to about 10 SRM.
FAQ
Why does my measured OG differ from the estimate?
Mash efficiency depends on your equipment, crush and technique. Use the efficiency you usually reach, not a generic default, so the estimate lines up with what you measure.
Does a longer boil always add more bitterness?
Only a little past 60 minutes. In the formula, going from 60 to 90 minutes raises utilization by about 7%, so late additions matter far more than extending the boil.
How accurate is the ABV formula?
The (OG - FG) x 131.25 formula is a common approximation and suits typical beer strengths. Treat it as an estimate, particularly for very strong or very light beers.