ABV from Gravity (Estimate)

Estimate alcohol by volume from an original and final gravity reading. A homebrewing convention, not an official measurement — see the disclaimer below.

Calculator

Non-regulatory estimate

Enter your original gravity (OG) and final gravity (FG) to estimate ABV.

⚠️ This is NOT an official or regulatory measurement. There is no government-recognized formula for gravity-based ABV — it is a common homebrewing/distilling convention only. It is never valid for a tax or label filing; those require an actual TTB-method measurement (distillation or densitometry).

Formula

Standard (linear)Best up to roughly 7% ABV — the common ABV ≈ (OG − FG) × 131.25 rule of thumb.High-gravity (Hall)More accurate above roughly 7% ABV — an alternate convention for stronger worts and washes.

Original gravity (OG)

Final gravity (FG)

Enter an original and final gravity to see the estimate.

Estimate only — a homebrewing/distilling convention (the Standard linear ABV ≈ (OG − FG) × 131.25 rule of thumb, or the High-gravity (Hall) alternate), not an official TTB filing, gauge record, or label-determinative measurement.

Reference tools, not a system of record. These free calculators are provided for convenience and general reference only. They are not a system of record and must not be used as the basis for any TTB or state compliance filing — even when a result is correct. Your official filings are governed by the applicable measurement and gauging methods and by your own production records.