Blood alcohol content calculator
Estimate your blood alcohol content (per mille) from the number of drinks, weight, sex and time elapsed.
Estimate (Widmark). The real result depends on many factors - never drive after drinking alcohol.
Approximate calculation. The exact amount is confirmed by the Social Insurance Board or the Tax and Customs Board - check the official source.
Last updated: 2026-06-03
How is BAC calculated?
Widmark formula: per mille = grams of alcohol / (weight × r) − 0.15 × hours, where r is 0.68 for men and 0.55 for women. One drink contains about 10 g of pure alcohol. The result is indicative - never drive after drinking alcohol.
How it is calculated
Formula
Widmark: per mille = A ÷ (m × r) − 0.15 × t, where A is grams of pure alcohol, m body mass in kg, r the distribution ratio (male 0.68 / female 0.55), t hours since drinking. One standard drink ≈ 10 g of alcohol.
Example
2 drinks (20 g), 80 kg male, 1 h → ≈ 0.37 − 0.15 ≈ 0.22 ‰. Indicative only.
Frequently asked questions
How is blood alcohol content calculated?+
The calculator uses the Widmark formula, accounting for the amount of alcohol consumed, body weight, sex and elapsed time.
Can I rely on the result for driving?+
No. The result is indicative only and does not replace a measurement. Drink-driving is dangerous and illegal.