Free tool
Proof Gallon Calculator
A proof gallon is one US liquid gallon of spirits at 100 proof (50% ABV), and it is the unit the TTB uses for excise tax and operational reports. Enter your wine gallons and proof below to convert to proof gallons instantly. This tool uses the same audited proof-gallon math as Spirit Sight, so it never disagrees with the product.
The formula
proof gallons = wine gallons x (proof / 100)
27 CFR 30.36 (definition of proof gallon). This tool uses the same calculation as the Spirit Sight platform. It is general information, not tax or legal advice.
What is a proof gallon?
One US liquid gallon of spirits at 100 proof (50% alcohol by volume). It is the TTB unit for excise tax and operational reporting.
What is the proof gallon formula?
Proof gallons = wine gallons x proof / 100. Multiply your wine gallons by the proof, then divide by 100. A 53-gallon barrel at 125 proof is 53 x 125 / 100 = 66.25 proof gallons.
How do you convert wine gallons to proof gallons?
Multiply the wine gallons (the actual liquid volume) by proof / 100. To go the other way, from proof gallons to wine gallons, divide proof gallons by proof / 100.
Is a proof gallon the same as a wine gallon?
No. A wine gallon is a liquid gallon regardless of strength; a proof gallon adjusts for alcohol content by the factor proof / 100. They are only equal at exactly 100 proof.
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