American bottles sometimes show a 'proof' number that looks alarmingly high next to the usual alcohol percentage.
How does U.S. proof relate to ABV?
It's exactly twice the ABV (80 proof = 40%) ✓
It's the same number
It's half the ABV
It's exactly twice the ABV (80 proof = 40%) In the U.S., proof is double the ABV — so 80 proof is 40% alcohol. The term dates to old tests of 'proving' spirit strength.