Proof ↔ ABV Converter
Live conversion — type in any field
Range: 0–200 proof
Range: 0–100%
Range: 0–175°proof
| Spirit | ABV | US Proof | UK Proof |
|---|---|---|---|
| Beer (typical) | 5% | 10° | 8.75° |
| Wine (typical) | 12% | 24° | 21° |
| Vodka (standard) | 40% | 80° | 70° |
| Gin (standard) | 40–47% | 80–94° | 70–82° |
| Whisky / Whiskey | 40–46% | 80–92° | 70–80.5° |
| Rum (standard) | 40% | 80° | 70° |
| Overproof rum | 63–75% | 126–150° | 110–131° |
| Cask strength whisky | 55–65% | 110–130° | 96–114° |
| Absinthe | 45–74% | 90–148° | 79–130° |
| New make spirit | 60–75% | 120–150° | 105–131° |
| Everclear / Spirytus | 95% | 190° | 166° |
| Azeotrope (max distillable) | 97.2% | 194.4° | 170° |
US Proof vs UK Proof vs ABV
Three different systems exist for measuring alcohol strength — and all three are still in active use today depending on where you are.
ABV (Alcohol by Volume) is the international standard used almost everywhere today. It expresses the percentage of pure ethanol in the total volume of liquid. A spirit at 40% ABV contains 40mL of ethanol for every 100mL of total liquid. ABV is used for all EU labelling, distillation calculations, and scientific purposes.
US Proof is exactly double the ABV percentage. A spirit at 40% ABV is 80 proof in the US. The system dates to early American taxation of alcohol, where 100 proof was defined as the minimum strength at which gunpowder soaked in spirit would still ignite — roughly 50% ABV.
UK Proof (British proof or Sykes proof) uses a different multiplier — 1.75 — based on a historical hydrometer system developed by Bartholomew Sykes in 1816. It was officially replaced by ABV in the UK in 1980 but still appears on older bottles and in historical recipes.
At 100° UK proof, a spirit is 57.15% ABV — this is why Navy Strength gin and rum is traditionally bottled at 57% ABV.
Why Does Navy Strength Mean 57%?
100° UK proof equals 57.15% ABV. The Royal Navy stored gunpowder and spirits in close proximity on ships. If a spirit was at or above 100° proof (57.15% ABV), it would not prevent gunpowder from igniting if accidentally soaked — a practical safety test. Spirits bottled at this strength became known as Navy Strength, a term still used for high-ABV gins and rums today.