What Is a Standard Drink Calculator?
A standard drink calculator works out how many standard drinks (or alcohol units) a beverage contains, based on its volume and alcohol by volume (ABV). Because a strong craft beer or a large pour can contain far more alcohol than people realize, counting standard drinks helps you track intake accurately and drink responsibly. Enter the drink's size and ABV, and the calculator returns the number of standard drinks.
How to Use the Calculator
- Enter the drink volume — in ounces or milliliters.
- Enter the ABV — the alcohol percentage on the label.
- Calculate — see the number of standard drinks.
How a Standard Drink Is Defined
A standard drink is defined by the grams of pure alcohol it contains, which varies by country. In the United States, one standard drink is about 14 grams of pure alcohol. The amount of pure alcohol in a beverage is:
Pure Alcohol (g) = Volume (mL) × (ABV ÷ 100) × 0.789
Dividing by the country's grams-per-standard-drink gives the number of standard drinks.
What Equals One US Standard Drink
| Beverage | Typical Serving | ABV |
|---|---|---|
| Regular beer | 12 oz | ~5% |
| Wine | 5 oz | ~12% |
| Distilled spirits | 1.5 oz | ~40% |
Each of these contains roughly 14 grams of pure alcohol — one US standard drink.
Why Counting Standard Drinks Matters
- Awareness: strong or large drinks can equal several standard drinks.
- Guidelines: health recommendations are expressed in standard drinks per day or week.
- Responsible drinking: tracking helps you stay within limits and plan safe transport.
Note: This is an informational tool. It does not estimate blood alcohol content or fitness to drive.
Frequently Asked Questions
What is a standard drink?
A standard drink is a fixed amount of pure alcohol — about 14 grams in the US. A 12 oz beer at 5%, a 5 oz glass of wine at 12%, and a 1.5 oz shot of spirits each equal roughly one standard drink.
How do you calculate standard drinks?
Multiply the volume by the ABV and the density of alcohol to get grams of pure alcohol, then divide by the grams in one standard drink (14 in the US).
How many standard drinks are in a bottle of wine?
A standard 750 mL bottle of wine at about 12% ABV contains roughly 5 standard drinks.
Does a standard drink mean the same everywhere?
No — the grams of alcohol per standard drink vary by country (for example, 14 g in the US, 10 g in the UK and Australia), so counts differ by region.
Is this standard drink calculator free?
Yes — it is completely free, requires no signup, and counts standard drinks from volume and ABV.