AustraliaTier 2
Brewhouse efficiency calculator
Grain bill and measured OG in. Your brewhouse efficiency percentage out.
Free·No sign-up·Last checked 2026-08-27
Formula
grain_lb = grain_kg × 2.20462. batch_gal = batch_L ÷ 3.78541.
Max points = grain_lb × (potential − 1) × 1000
Actual points = (OG − 1) × 1000 × batch_gal
Efficiency% = actual points ÷ max points × 100
Worked example. 4.5 kg grain (9.92 lb) at 1.037 potential, 19 L (5.02 gal) batch, OG 1.050 → 251 actual points ÷ 367 max points = 68.4%.
Method
Points-per-pound-per-gallon, converted from metric inputs
Grain "potential" is conventionally expressed in points per pound per gallon, a brewing-reference scale with no direct metric equivalent. This calculator converts your kg and L inputs to the traditional lb/gal basis internally, runs the standard formula, and reports the result as a percentage — which is unit-agnostic either way.
Questions
Most home all-grain setups land between 65% and 80%. Below 60% usually points to a crush that's too coarse or a stuck/channeled sparge; above 85% is unusual outside commercial-scale equipment.
1.037, or 37 points per pound per gallon in the traditional brewing reference scale, is a common average for base malt. Specialty and crystal malts run lower; check your maltster's spec sheet for an exact figure if you want a more precise number.