Free blood alcohol calculator

See how alcohol could affect your blood alcohol level later.

Add a typical drink, tell us how long you drank for, and see a simple hour-by-hour guide to how your blood alcohol level may rise and fall.

This is an estimate for learning and reflection, not a way to decide whether it is safe to drive or do anything risky.

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Number of drinks

Size of each drink

Type of drink

Time spent drinking

Sex

Weight

A guide, not a green light

Blood alcohol calculators are estimates. If you are driving, operating machinery, looking after someone, or making an important decision, the safest assumption is that alcohol still matters.

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