Beer Original Gravity Estimate Calculator

Work out beer original gravity estimate instantly with clear inputs, formula shown and shareable results.

About Beer Original Gravity Estimate Calculator

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.

Formulas

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

Worked example

With the default values below, Beer Original Gravity Estimate Calculator returns Original Gravity of 1.05625. Change any input above and every figure here is recalculated in your browser.

Inputs used

Total Grain Billminimum 0 kg: 5 kg
Average Grain Extract Potentialminimum 0 points per kg per litre: 300 points per kg per litre
Batch Volume Into Fermenterminimum 0 L: 20 L
Mash Efficiencyaccepts 1–100 %: 75 %

Results

Original Gravity: 1.05625
Gravity Points: 56.25
Degrees Plato: 13.863
Gravity At 100% Efficiency: 1.07500

Step by step

1Values used
2Original gravity
3Plato conversion
4Original Gravity= 1.05625
5Gravity Points= 56.25
6Degrees Plato= 13.863
7Gravity At 100% Efficiency= 1.07500

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 5 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

What limits mash efficiency?

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.

Why does batch volume matter so much?

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.