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ABV Calculator
Find your beer or wine's alcohol by volume from the original and final gravity — plus ABW, attenuation, and calories.
Short answer
Alcohol by volume (ABV) = (OG − FG) × 131.25. With an original gravity of 1.050 and a final gravity of 1.010, that's 5.25% ABV. Enter your two hydrometer readings below for ABV, alcohol by weight, apparent attenuation, and calories — with a more accurate formula for strong beers.
Gravity before fermentation.
Gravity after fermentation.
Alcohol by volume
5.25%
- Alcohol by weight (ABW)
- 4.17%
- Apparent attenuation
- 80%
- Calories (per 12 oz)
- 165
How to calculate ABV
Take a hydrometer reading before you pitch yeast — that's your original gravity (OG) — and another when fermentation is done, the final gravity (FG). The difference is the sugar the yeast converted to alcohol and CO₂. Multiply it by 131.25 for ABV. Above about 7% the standard formula reads a touch low, so switch to the alternate formula for strong beers, meads, and wines.
Typical ABV and IBU by beer style
Where common styles land — handy for targeting a recipe or checking a finished batch against the guidelines.
| Beer style | Typical ABV | Typical IBU |
|---|---|---|
| American Light Lager | 2.8–4.2% | 8–12 |
| American Pale Ale (APA) | 4.5–6.2% | 30–50 |
| American IPA | 5.5–7.5% | 40–70 |
| Double / Imperial IPA | 7.5–10% | 60–120 |
| Stout (Dry Irish) | 4.0–4.5% | 25–45 |
| Imperial Stout | 8–12% | 50–90 |
| Hefeweizen | 4.3–5.6% | 8–15 |
| Saison | 5–7% | 20–35 |
| Belgian Tripel | 7.5–9.5% | 20–40 |
| Barleywine | 8–12% | 35–70 |
How we calculate this
Every figure comes from a standard, published homebrewing formula — shown, not hidden:
- ABV. standard ABV = (OG − FG) × 131.25; the alternate (Novotný) formula corrects the under-read on strong beers above ~7%.
- ABW & attenuation. ABW = ABV × 0.79336; apparent attenuation = (OG − FG) ÷ (OG − 1) × 100.
- Calories. calories per 12 oz sum the alcohol and residual-carbohydrate contributions from OG and FG (the standard brewer's method).
- IBU & priming. bitterness uses the Tinseth utilization model; priming sugar uses temperature-based residual CO2 and ~4 g dextrose per litre per volume of CO2.
Assumptions
- Gravity readings assume a calibrated hydrometer at its reference temperature; correct for temperature for best accuracy.
- The × 131.25 constant is an approximation — real ABV depends on the exact sugar profile.
- IBU is an estimate; actual bitterness varies with hop age, form (pellet vs whole), and hot-side losses.
- Planning tools, not lab measurements — take a final hydrometer reading to confirm.
Last reviewed: July 19, 2026
Frequently asked questions
How do you calculate ABV?+
The standard formula is ABV = (OG − FG) × 131.25, where OG is your original gravity (before fermentation) and FG is your final gravity (after). For example, an OG of 1.050 and FG of 1.010 gives (1.050 − 1.010) × 131.25 = 5.25% ABV. Enter your two gravity readings above and the calculator does it instantly, plus ABW, attenuation, and calories.
What's the difference between the standard and alternate ABV formula?+
The standard formula (× 131.25) is simple and accurate up to about 6–7% ABV. Above that it slightly under-reads, so the alternate formula — ABV = (76.08 × (OG − FG) / (1.775 − OG)) × (FG / 0.794) — is more accurate for strong beers and wines. Both are offered here; use the alternate for high-gravity brews.
What is apparent attenuation?+
Apparent attenuation is the percentage of sugars the yeast fermented, measured with a hydrometer: (OG − FG) ÷ (OG − 1) × 100. A typical ale finishes around 75%; a highly attenuative yeast or a simple-sugar recipe can exceed 80%. It's 'apparent' because alcohol is lighter than water, so the hydrometer reads a bit low.
What is ABW and how does it relate to ABV?+
ABW is alcohol by weight, versus ABV which is by volume. Because alcohol is less dense than water, ABW is about 0.79 × ABV — so a 5% ABV beer is roughly 4% ABW. US brewers label ABV; a few older or international measures use ABW.
How do I use the IBU and priming sugar calculators?+
The IBU calculator estimates bitterness from your hop additions (alpha acid %, weight, and boil time) using the Tinseth model. The priming sugar calculator tells you how much sugar to add at bottling to hit a target carbonation, based on your beer's temperature and volume. Both are linked from this page as part of the homebrew suite.
Are these brewing calculators accurate?+
They use the standard, widely-accepted homebrewing formulas (ABV, Tinseth IBU, temperature-based priming), so they're reliable planning tools. Real-world results vary with hydrometer calibration, temperature, yeast health, and hop freshness — always take a final hydrometer reading, and treat carbonation figures as a target to dial in.
Related tools
Homebrew suite
Uses the standard homebrewing formulas — a reliable planning tool. Real results vary with hydrometer calibration and temperature; always take a final reading.