Whisky · Explainer
What do ABV and proof mean on a bottle?
ABV stands for alcohol by volume: the share of alcohol in the volume of the drink. The American proof is exactly twice that percentage, so 40 percent is 80 proof. In the European Union the effective alcoholic strength by volume must be on the label for drinks with more than 1.2 percent by volume of alcohol.
In brief
The key figures
| ABV | Alcohol by volume, the percentage by volume of alcohol in the drink |
|---|---|
| American proof | Twice the percentage by volume, at 60 degrees Fahrenheit |
| Example | 40 percent alcohol is 80 proof |
| Proof gallon | A gallon at 60 degrees Fahrenheit with 50 percent ethanol by volume |
| United States label | Percentage alcohol by volume mandatory, proof allowed in the same field of vision |
| Tolerance United States | Plus or minus 0.3 percentage points relative to the stated value |
| European Union label | Actual alcoholic strength by volume mandatory above 1.2 percent by volume |
| British proof | Replaced by percent by volume as of 1 January 1980 |
What exactly does ABV mean?
ABV stands for alcohol by volume. The number indicates which part of the volume consists of pure alcohol, so 40 percent means 40 millilitres of alcohol per 100 millilitres.
Temperature is part of it, because liquid expands when warm. The Dutch Alcohol Act uses a temperature of 20 degrees Celsius.
On European labels you usually see something like alc. 40% vol. The percentage always refers to volume and not to weight.
What is proof and how do you convert it?
Proof is the American measure of alcoholic strength. The federal rules define proof as the ethanol content at 60 degrees Fahrenheit, expressed as twice the volume percentage.
Converting is therefore simple. Divide the proof by two and you have the percentage: 80 proof is 40 percent, 100 proof is 50 percent and 114 proof is 57 percent.
In those same rules a proof gallon is a gallon of liquid at 60 degrees Fahrenheit that contains 50 percent ethanol by volume. That unit is used in American tax rules.
Why does the British proof turn out differently?
The British system was not based on 50 percent. One hundred degrees of British proof was higher, so a British proof number was never equal to double the percentage.
In the British regulation that closed the system, a gallon of spirit at proof counts as 2.595 litres of pure alcohol. Converted, that comes to well over 57 percent of the volume.
The United Kingdom switched to percent by volume on 1 January 1980. You will therefore only still come across degrees proof on British labels from before that date.
What must the label say about alcohol?
In the European Union the actual alcoholic strength by volume is mandatory for drinks with more than 1.2 percent alcohol by volume. Regulation 1169/2011 governs that statement.
In the United States, the federal rules for spirits require the percentage of alcohol by volume to be on the label. Proof is allowed in addition, provided it is in the same field of view as the mandatory statement.
Permitted spellings include 40% alc/vol, alc. 40 percent by vol. and 40% Alcohol by Volume.
How accurate is the percentage on the bottle?
A small deviation is allowed. The American rules permit a difference of plus or minus 0.3 percentage points between the stated and the actual alcohol content.
A bottle with 46 percent on the label can therefore, under that rule, lie between 45.7 and 46.3 percent. For use at home that makes little difference.
With cask strength you often see a percentage with a decimal, for example 57.4 percent, because every bottling has its own measured strength.
From the shop in Bathmen
How much whisky is there in Bathmen?
In de winkel in Bathmen staan 3.984 whisky's van 589 verschillende merken uit 31 landen. De prijzen lopen van € 5,99 tot € 12.500,00. Het alcoholpercentage loopt van 10% tot 73,7%.
- 1770 Glasgow Distillery 2nd Release 46% · 50 cl · Scotland
- 1770 Glasgow Distillery Red Wine & Ruby Port Cask Finish 57.5% · 70 cl · Scotland
- 1770 Glasgow Distillery The Original 46% · 70 cl
- 1770 Glasgow Distillery The Original Cask Strength #2 59.5% · 70 cl
- 1770 Glasgow Distillery Triple Distilled 46% · 70 cl
- 1770 Glasgow Distillery Triple Distilled Release No.1 46% · 50 cl
- 1770 Glasgow Distillery White Port Cask Finish 53.3% · 70 cl
- 1770 Glasgow Single Malt 52% · 70 cl · Scotland
- 1792 Small Batch 46.85% · 75 cl · United States
- A Highland Distillery 2005 – 16 Years Old – First Cask 58.3% · 70 cl · Scotland
Related questions
What do limited release and edition size mean on a bottle?What does bottled in bond mean?What does cask finish mean?
Short answer
Short answers to related questions
- How many proof is 40 percent alcohol?
- 80 proof. American proof is exactly twice the alcohol by volume.
- Is 100 proof the same in the United States and in the United Kingdom?
- No. In the United States 100 proof equals 50 percent alcohol. In the old British system proof was higher, a good 57 percent, and that system disappeared on 1 January 1980.
- Why does it not say proof on European bottles?
- The European rules require the actual alcoholic strength by volume in percent by volume. Proof is an American measure and is not a mandatory statement here.
- What does cask strength mean?
- That the whisky has been bottled without dilution with water, so that the stated percentage follows the strength from the cask.
The reasoning
Sources
- 27 CFR 5.1 Definitions, eCFR, Alcohol and Tobacco Tax and Trade Bureau (accessed 4 September 2026)
- 27 CFR 5.65 Alcohol content, eCFR, Alcohol and Tobacco Tax and Trade Bureau (accessed 4 September 2026)
- Verordening (EU) nr. 1169/2011, artikel 9 lid 1 onder k, EUR-Lex (accessed 4 September 2026)
- The Alcoholic Liquors (Amendment of Enactments Relating to Strength and to Units of Measurement) Order 1979, legislation.gov.uk (accessed 4 September 2026)
Deze pagina is geschreven en gecontroleerd door ’t Bockje Bathmen, slijterij aan de Brink 2 in Bathmen. Laatst bijgewerkt op 27 oktober 2026.
Verkoop van alcohol onder de 18 jaar is verboden. NIX18.