Is a glass always one standard drink?
No. Serving size and strength both matter. A larger glass or stronger drink contains more alcohol. This calculator measures alcohol in the drink, not your blood alcohol level.
How much pure alcohol is in a serving?
| Volume | Alcohol strength | Pure alcohol |
|---|---|---|
| 12 US fl oz | 5% | ≈ 0.6 US fl oz |
| 5 US fl oz | 12% | ≈ 0.6 US fl oz |
| 1.5 US fl oz | 40% | ≈ 0.6 US fl oz |
A 12 US fl oz drink at 5% contains 0.6 US fl oz of pure alcohol — about one US standard drink. Multiply the serving volume by the alcohol percentage and divide by 100. This is the alcohol in the drink, not your blood alcohol level.
