Mash Efficiency Calculator
Enter each grain with its weight and potential, your measured original gravity and batch size, to see how much of the available extract you actually captured - and what the same grain bill would give at 100%.
Results
- Potential gravity points
- 166.5 pts
- Captured gravity points
- 950 pts
- At 100% efficiency
- 1.009 SG
How efficiency is calculated
Every pound of grain carries a potential in gravity points per gallon (PPG). The potential of your bill is the sum of weight × potential. Your captured points are (measured SG - 1) × 1000 × gallons. Divide captured by potential and you have efficiency. Typical home systems land between 65% and 80%.
Efficiency starts at dough-in: set the water temperature right with the strike water temperature calculator, and read your gravity accurately using the hydrometer temperature correction before you measure here.
Frequently asked questions
What is a good mash efficiency number?
Typical home systems land between 65% and 80%. Batch sparging usually reaches 70-78%, fly sparging a few points higher, and BIAB with a fine crush can exceed 80%. Biabacus-style no-sparge full-volume mashes trade efficiency for simplicity, so 60-70% is normal there. Log several brews before chasing a number.
Why is my efficiency lower than expected?
The usual suspects, roughly in order: a coarse crush (whole kernels never release their extract), a stuck or short sparge, mashing outside pH 5.2-5.6, or simply leaving too much wort behind in the kettle and pumps. Improve one variable at a time and re-measure with this calculator rather than adjusting everything at once.
Should I use mash efficiency or brewhouse efficiency?
Mash efficiency measures how much extract you pulled from the grain into the kettle; brewhouse efficiency also subtracts trub, hops and transfer losses on the way into the fermenter. This calculator computes brewhouse-style efficiency from the volume that actually reaches the fermenter, which is the number you should use when scaling recipes.
Why are potentials still in PPG when I enter metric weights?
Points per pound per gallon is the native unit of malt analysis sheets and nearly every recipe software, and it converts cleanly: pounds = kg x 2.2046. Keeping the potential in PPG avoids a second conversion error - the calculator converts your metric weights and batch size internally, and the result is identical either way.