BAC Calculator

A rough sense of how alcohol may be affecting you, based on how much you have had, your weight and the time that has passed. For awareness only.

SexWeight (kg)Standard drinksHours since first drink

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Part of Seri Calm, one of Seri's health companions.

How it's calculated

We use the Widmark formula, treating one standard drink as about 10g of pure alcohol, and subtract roughly 0.015 percent per hour as your body clears it.

How to read your result

This is an estimate and nothing more. Real blood alcohol depends on food, medication, metabolism and the exact drinks. It cannot tell you whether you are safe or legal to drive, so never use it to make that call.

Common questions

Can I use this to decide if I can drive?

No. This is an awareness tool, not a breathalyser. If you have been drinking at all, the safe choice is not to drive.

How fast does alcohol leave my system?

What counts as a standard drink?

Method: Widmark formula (estimate only).