How to use the alcohol units calculator
- Choose whether sizes are in US fluid ounces or milliliters.
- For each drink enter the size of one, its strength (ABV %) and how many you had. The starting rows are examples; replace them with your own.
- Open More options to set how much pure alcohol counts as one unit and one standard drink where you live.
- Read the units, standard drinks, pure alcohol in milliliters and grams, and the table by drink. Copy, Print or export the CSV.
Formula
pure alcohol (mL) = size in mL x ABV / 100 x number of drinks
units = pure alcohol (mL) / mL per unit
grams = pure alcohol (mL) x 0.789
standard drinks = grams / grams per standard drink
A US fluid ounce is 29.5735295625 mL. Ethanol density is taken as 0.789 grams per milliliter. The unit size starts at 10 mL and the standard drink at 14 grams, both as editable examples.
Two beers, a glass of wine and a shot
Two 12 ounce beers at 5% hold 2 x 12 x 29.5735 x 0.05 = 35.49 mL of pure alcohol. A 5 ounce glass of wine at 12% holds 17.74 mL, and a 1.5 ounce shot of spirits at 40% holds 17.74 mL.
The total is 70.98 mL, which is 7.10 units at 10 mL each. By weight that is 70.98 x 0.789 = 56.0 g, or 4.00 standard drinks at 14 g each.
Why units and standard drinks differ
Countries define a unit or a standard drink with different amounts of pure alcohol, and some define it by volume while others use weight. The page lets you set both, so you can match the definition in your country or on a label.
The strength on a bottle is the percentage of the liquid that is alcohol by volume. Craft beers, wine and mixed drinks often differ from the common example sizes, so use the size and strength you actually poured.
What the page does not do
This tool is arithmetic. It does not say how much is safe or legal, and it cannot tell how alcohol will affect you, which depends on body size, food, time, medicines and health. Never use it to decide whether you can drive.
For brewing and home recipes, the ABV calculator works out strength from gravity readings, and the party food and drink calculator plans quantities for guests. If you are worried about your own drinking, talk to a health professional.
Assumptions and limits
- Size, strength and count are the numbers you enter. A strength of 0 is allowed for alcohol-free drinks.
- The unit size (10 mL) and standard drink (14 g) are editable examples. They are not official definitions for any country.
- Ethanol density is fixed at 0.789 grams per milliliter, which varies slightly with temperature.
- This is general information and not medical advice. Nothing is stored or uploaded.
Frequently asked questions
How do I calculate units of alcohol?
Multiply the volume in milliliters by the strength as a percentage, divide by 100 to get the milliliters of pure alcohol, then divide by the milliliters in one unit. A 500 mL drink at 4.5% holds 22.5 mL, or 2.25 units at 10 mL per unit.
What is a standard drink?
A standard drink is a fixed amount of pure alcohol used to compare drinks. Its size differs between countries, so the page lets you enter the grams that apply to you. The starting 14 grams is only an example.
Why does a bigger glass of wine have more alcohol?
Because the amount of pure alcohol grows with the volume you pour. A large glass can hold the alcohol of two small ones, which is why the size of one drink matters as much as its strength.
Can this tell me if I am safe to drive?
No. It only totals the alcohol in the drinks you list. How alcohol affects a person depends on many things, so never use this page to decide whether you can drive.