United StatesTier 1
ABV to proof calculator
US proof is exactly twice ABV. Enter either value — the other updates live.
Free·No sign-up·Last checked 2026-08-27
Formula
Proof = ABV × 2ABV = Proof ÷ 2Worked example. 40% ABV × 2 = 80 proof. 100 proof ÷ 2 = 50% ABV.
Questions
No. US proof is exactly twice ABV. UK proof used a different scale (about 1.75× ABV) before it was retired in 1980 in favor of ABV — this calculator is US proof only.
Proof is a historical US and Canadian labeling convention, mostly seen on spirits. ABV is the internationally standard figure and the one required on most labels worldwide.