Work out beer original gravity estimate instantly with clear inputs, formula shown and shareable results.
Gravity points are grain weight times extract potential times mash efficiency, divided by batch volume. A well-modified pale malt yields around 300 points per kilogram per litre at full conversion. Typical homebrew mash efficiency is 70-80%, and commercial breweries reach 85-92% with better milling and lautering.
Original gravity
Points = grain (kg) x potential x efficiency / volume (L); OG = 1 + points / 1000
Plato conversion
Plato = -616.868 + 1111.14 SG - 630.272 SG^2 + 135.997 SG^3
Crush fineness, mash pH and temperature, water-to-grain ratio, sparge technique and lauter bed depth. A coarse crush is the most common cause of low efficiency.
Gravity is a concentration, so the same grain in less wort gives higher gravity. Boil-off and trub losses must be accounted for or the measured gravity will not match the target.