Homebrewing Efficiency Calculator
Calculate your homebrew mash efficiency and brewhouse efficiency.
Know how much fermentable sugar you extracted and how to improve your yield.
Homebrew efficiency measures how well you extract fermentable sugars from grain during the mash. Higher efficiency means more sugar (and therefore more alcohol) from the same amount of grain.
Two key efficiency numbers:
- Mash efficiency: sugar extracted from the grain into the wort
- Brewhouse efficiency: sugar that actually makes it into the fermenter (accounts for losses)
The gravity point system:
Instead of working directly with specific gravity (SG), brewers use gravity points:
Gravity Points = (SG - 1) × 1000
Example: SG of 1.052 = 52 gravity points
Potential extract by grain type:
Each pound of grain has a maximum potential extract (in gravity points per pound per gallon):
| Grain Type | Potential (PPG) | Typical |
|---|---|---|
| 2-row pale malt | 38 PPG | Most common base malt |
| 6-row pale malt | 35 PPG | Lower extract than 2-row |
| Pilsner malt | 37 PPG | European lagers |
| Munich malt | 35 PPG | Color and flavor |
| Crystal / Caramel malt | 34 PPG | Sweetness and color |
| Wheat malt | 39 PPG | Hefeweizens, wheat beers |
| Oats (flaked) | 36 PPG | Body, haziness |
| Roasted barley | 25 PPG | Stouts, color |
Which efficiency are you measuring?
This is where most efficiency arguments on brewing forums come from: two people quote numbers that are not measuring the same thing. Both use the same formula, and the difference is entirely where you take the reading.
Efficiency (%) = (Gravity Points × Volume in gallons) ÷ (Grain Weight in lbs × Potential PPG) × 100
Measure gravity and volume in the kettle before the boil and you get mash efficiency: how much sugar you got out of the grain. That is the number this calculator gives you from the four required fields, and it is the one that tells you whether your crush and your sparge are working.
Measure them again as the wort goes into the fermenter and you get brewhouse efficiency: how much sugar you actually get to ferment. It is always the lower of the two, because hops, hot break and trub keep some wort in the kettle. That is the number recipe software uses to hit a target original gravity, so it is the one to plug into your recipe builder. Fill in the two optional fields and this calculator reports it alongside the mash figure and tells you how much you left behind in the kettle.
A five to ten point gap between them is ordinary. A much bigger one usually means a lot of wort is being abandoned under the hop bed.
Typical efficiency ranges:
| System Type | Typical Efficiency |
|---|---|
| Extract brewing | N/A (uses pre-made extract) |
| Partial mash | 55–70% |
| All-grain (BIAB) | 65–80% |
| All-grain (3-vessel) | 70–85% |
| Professional brewery | 85–95% |
What affects efficiency:
- Crush quality: finer crush = more sugar extracted (but can clog a false bottom)
- Mash temperature: 148–158°F (64–70°C) for standard conversion
- Mash time: minimum 60 minutes for full conversion
- Water-to-grain ratio: thinner mashes typically extract slightly more efficiently
- Sparge technique: fly sparging extracts more than batch sparging
- Grain freshness: old, stale grain has lower potential
Improving low efficiency:
- Crush grain finer (but not flour-fine for traditional setups)
- Ensure mash temperature stays stable
- Extend mash to 90 minutes
- Stir the mash gently every 15 minutes
- Check for dough balls in the mash: pockets of dry grain kill efficiency
How we build and check this calculator
This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
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