What this alcohol gram calculator does
This calculator estimates how many grams of pure alcohol are in a drink based on serving size and ABV (alcohol by volume). You can calculate alcohol grams per drink and total grams across multiple drinks.
Tracking alcohol in grams can be more accurate than counting “drinks,” because drink sizes and alcohol strength vary widely. A strong IPA, a large glass of wine, and a double pour of liquor can differ a lot in actual alcohol content.
How alcohol grams are calculated
Formula used
The calculator uses the standard chemistry-based conversion:
- Pure alcohol volume (mL) = drink volume (mL) × ABV as decimal
- Alcohol grams = pure alcohol volume (mL) × 0.789 g/mL
The value 0.789 g/mL is the density of ethanol at room temperature, which is commonly used in nutrition and public health calculators.
Unit conversion
If you enter fluid ounces, the calculator first converts to milliliters using: 1 US fl oz = 29.5735 mL.
Common examples
Example 1: Beer
A 12 fl oz beer at 5% ABV contains about 14 grams of alcohol. That is roughly one US standard drink.
Example 2: Wine
A 5 fl oz wine at 12% ABV contains about 14 grams of alcohol, again close to one standard drink.
Example 3: Spirits
A 1.5 fl oz shot at 40% ABV contains about 14 grams of alcohol.
Why grams of alcohol are useful
- More precise tracking than “number of drinks” alone
- Helpful for calorie estimation (alcohol has 7 calories per gram)
- Useful for comparing different beverage types fairly
- Supports harm-reduction goals and moderation plans
Important notes and limitations
Label values are approximate
ABV on labels can vary slightly by batch and serving pour size may differ from what is listed. Your real intake may be somewhat higher or lower than the estimate.
Large servings change everything
A “single drink” can contain multiple standard drinks if the serving is large or high proof. Always check both size and ABV.
Not medical advice
This tool is educational and should not be used to determine driving safety, legal intoxication, or medical fitness. If alcohol use is affecting your health or daily life, speak with a qualified professional.
Quick FAQ
How many grams are in one standard US drink?
In the United States, one standard drink is generally defined as 14 grams of pure alcohol.
Can I use this for cocktails?
Yes. Enter the total final volume and an estimated ABV, or calculate each alcoholic ingredient separately and add the grams.
Does this calculator work internationally?
Yes for grams calculation. However, “standard drink” definitions vary by country, so compare against local guidelines if needed.