Alcohol Unit Calculator

1. Select your drink type. Choose Beer (12 oz at 5%), Wine (5 oz at 12%), Shot (1.5 oz at 40%), or Custom if your drink has a different volume or ABV. Craft beers and cocktails often have higher ABV than standard options.
2. Enter the number of drinks. Use decimals for partial servings. Half a glass of wine is 0.5.
3. For BAC estimation, enter your body weight and biological sex. The BAC calculation uses the Widmark formula, which requires these inputs. Women typically have a higher BAC than men at the same intake due to lower body water percentage.
4. Read your results. The calculator shows UK alcohol units, US standard drinks, grams of pure alcohol, estimated BAC, and estimated hours until sober.

UK Alcohol Unit

1 UK unit = 10 ml (8 g) of pure ethanol. The UK guidelines recommend no more than 14 units per week for both men and women, spread over at least 3 days.

UK Units = (Volume in ml × ABV%) / 1000

Example: Pint of 5% beer (568 ml)
UK Units = (568 × 5) / 1000 = 2.84 units

US Standard Drink

1 US standard drink contains 14 grams (17.7 ml) of pure alcohol. The US Dietary Guidelines define moderate drinking as up to 1 standard drink per day for women and up to 2 for men.

Pure Alcohol (ml) = Volume (ml) × (ABV / 100)
US Standard Drinks = Pure Alcohol (ml) / 17.7

Example: 12 oz beer (355 ml) at 5%:
Pure alcohol = 355 × 0.05 = 17.75 ml
Standard drinks = 17.75 / 17.7 = 1.0

BAC Estimation (Widmark Formula)

BAC = (Alcohol in grams) / (Body weight in grams × r) × 100

r = 0.68 for men, 0.55 for women
(r reflects the proportion of body water)

Example: 160 lb (72.6 kg) male, 3 beers = 42g alcohol
BAC = 42 / (72,600 × 0.68) × 100 = 0.085%

The liver metabolizes approximately 0.015% BAC per hour (about 1 standard drink per hour for most people). "Sobering up" faster by drinking coffee, eating, or sleeping does not speed this process.