Convert us proofs to british proof (historic)s
1 proof (US) = 0.875 proof (UK) — exactly. Both units are defined against the SI, so this factor is a fraction, not an approximation.
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Show this value in all 6 alcohol strength units
- Volume fractions v/v 0.005
- Percent alcohol by volumes % ABV 0.5
- Degree Gay-Lussacs °GL 0.5
- Per mille alcohol by volumes ‰ ABV 5
- US proofs proof (US) 1
- British proof (historic)s proof (UK) 0.875
Every row is US proof (proof (US)) converted through the volume fraction, in exact rational arithmetic.
How to convert us proofs to british proof (historic)s
Multiply the number of us proofs by 0.875 to get british proof (historic)s.
The exact factor is 0.875 — as a fraction, 7/8.
British proof (historic): Historic convention: 100 proof equals 4/7 alcohol by volume. Modern UK labels use ABV.
US proof to British proof (historic) conversion table
| US proofs (proof (US)) | British proof (historic)s (proof (UK)) |
|---|---|
| 1 proof (US) | 0.875 |
| 2 proof (US) | 1.75 |
| 3 proof (US) | 2.625 |
| 5 proof (US) | 4.375 |
| 10 proof (US) | 8.75 |
| 20 proof (US) | 17.5 |
| 25 proof (US) | 21.875 |
| 50 proof (US) | 43.75 |
| 100 proof (US) | 87.5 |
| 250 proof (US) | 218.75 |
| 500 proof (US) | 437.5 |
| 1000 proof (US) | 875 |
British proof (historic) to US proof conversion table
| British proof (historic)s (proof (UK)) | US proofs (proof (US)) |
|---|---|
| 1 proof (UK) | 1.142 857 1 |
| 2 proof (UK) | 2.285 714 3 |
| 3 proof (UK) | 3.428 571 4 |
| 5 proof (UK) | 5.714 285 7 |
| 10 proof (UK) | 11.428 571 |
| 20 proof (UK) | 22.857 143 |
| 25 proof (UK) | 28.571 429 |
| 50 proof (UK) | 57.142 857 |
| 100 proof (UK) | 114.285 71 |
| 250 proof (UK) | 285.714 29 |
| 500 proof (UK) | 571.428 57 |
| 1000 proof (UK) | 1142.8571 |
Frequently asked
How many british proof (historic)s are in a us proof?
One us proof equals 0.875 british proof (historic)s (proof (US) → proof (UK)). That figure is exact, not rounded.
How do you convert us proofs to british proof (historic)s?
Multiply the number of us proofs by 0.875 to get british proof (historic)s.
What is 1 proof (UK) in us proofs?
One british proof (historic) is 1.142857143 us proofs.
What is 10 proof (US) in proof (UK)?
10 proof (US) = 8.75 proof (UK).
What exactly is a british proof (historic)?
Historic convention: 100 proof equals 4/7 alcohol by volume. Modern UK labels use ABV.