Alcohol Unit Calculator: Count Standard Drinks and Stay Informed
Calculate the number of standard drinks and alcohol units in any beverage. Track your alcohol intake and understand UK units vs. US standard drinks.
"How many drinks have I had?" sounds simple until you realize a 9% IPA in a pint glass is very different from a 4.2% light beer in a 12 oz can. The CalcHub Alcohol Unit Calculator calculates how many standard drinks or UK units are in any pour, based on the drink's volume and ABV.
What Is a "Standard Drink"?
A standard drink contains 14 grams of pure alcohol (US definition). Other countries use different standards:
| Country | Pure Alcohol per Standard Drink |
|---|---|
| United States | 14 grams |
| United Kingdom (1 unit) | 8 grams |
| Australia | 10 grams |
| Canada | 13.6 grams |
| European Union | 10 grams |
Drinks That Surprise People
Most people significantly underestimate alcohol intake because of these common misconceptions:
| Drink | Volume | ABV | US Standard Drinks |
|---|---|---|---|
| Light beer (can) | 12 oz | 4.2% | 1.0 |
| Regular beer (can) | 12 oz | 5.0% | 1.2 |
| Craft IPA (pint glass) | 16 oz | 7.5% | 2.4 |
| House wine (generous pour) | 8 oz | 13% | 2.0 |
| Restaurant "glass" of wine | 6 oz | 13% | 1.5 |
| Standard spirits (shot) | 1.5 oz | 40% | 1.0 |
| Long Island Iced Tea | 8–10 oz | ~17% combined | 2.5–3.5 |
| Cocktail (4 oz, 25% ABV) | 4 oz | 25% | 2.0 |
The Formula
Standard drinks = Volume (mL) × ABV (as decimal) × 0.789 (density of alcohol) ÷ 14Or in simpler form for quick calculation:
Standard drinks (US) = oz × ABV% ÷ 0.6
Health Guidelines (for reference only)
| Organization | Low-Risk Guidelines |
|---|---|
| NIAAA (US) | Up to 4 drinks/day, 14 drinks/week (men); 3 drinks/day, 7/week (women) |
| NHS (UK) | No more than 14 units/week, spread over 3+ days, with some alcohol-free days |
| WHO (2023) | "No safe level of alcohol consumption" for cancer risk |
Blood Alcohol Content (BAC) Estimate
The calculator can provide a rough BAC estimate using the Widmark formula:
BAC (g/dL) = (alcohol consumed in grams / (body weight in grams × 0.68 for men / 0.55 for women)) × 100This is an estimate only. BAC varies by food consumed, metabolic rate, medications, hydration, and other factors. The legal driving limit in the US is 0.08% BAC in most states.
Does drinking water between drinks lower your BAC?
Water doesn't reduce BAC — alcohol metabolizes at a fixed rate of about one standard drink per hour regardless of hydration. Water does reduce dehydration symptoms and helps you slow your drinking pace. There's no way to "sober up faster."
What if I don't know my beer's ABV?
Domestic light beers (Bud Light, Coors Light) are around 4.2%. Regular domestic beers are ~5%. Most craft beers range from 5–8%. The calculator includes a searchable database of common beers with their ABVs.
Are alcohol units the same as calories?
No. Alcohol has 7 kcal per gram (nearly as calorie-dense as fat at 9 kcal/g). A UK unit (8g alcohol) contains 56 alcohol calories, but drinks also contain carbohydrates from sugar and malt. A pint of 5% beer has roughly 200–250 total calories.
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