Recipe calculator
Add your grain and hops. Read off strength, bitterness and colour, then scale the whole recipe to your batch.
Grain and sugar
Hops (boil additions)
The swatch is an approximation of the colour of a thin glass of beer.
ABV from OG and FG
The formulas
OG. Each grain contributes points per pound per gallon (ppg), multiplied by your brewhouse efficiency and divided by the volume. Gravity points = sum of (pounds x ppg) x efficiency / gallons. OG = 1 + points / 1000.
ABV. The standard formula is ABV = (OG - FG) x 131.25. For strong beers the alternative ABV = 76.08 x (OG - FG) / (1.775 - OG) x (FG / 0.794) is closer. Both are in common use; see the explanation of beer measurement on Wikipedia.
IBU. Glenn Tinseth's formula: IBU = mg/L of alpha acid x utilisation, where utilisation = 1.65 x 0.000125^(OG - 1) x (1 - e^(-0.04 x minutes)) / 4.15. His article is Hop Utilization on realbeer.com. Whirlpool and dry-hop additions are not included.
Colour. Malt colour units MCU = sum of (grain Lovibond x pounds) / gallons. SRM = 1.4922 x MCU^0.6859, the Morey equation, which is the one most brewing software uses. EBC = SRM x 1.97. See Standard Reference Method.
Ingredient values (ppg and Lovibond) are typical figures. Your maltster's spec sheet will be more exact. Compare your numbers to the BJCP style guidelines.