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Alcohol BAC Timeline Calculator

Blood alcohol level and time to sober up.

Enter your values

ⓘ Live results

Results
Estimated BAC
0.073%
Hours until sober (BAC 0)
4.9
Legal driving limit note
Common limit is 0.05-0.08% — check your local law

Quick answer

Blood alcohol content is estimated from alcohol consumed, body weight, sex and time elapsed, using the Widmark formula.

BAC = (alcohol grams / (weight(g) x r)) - 0.015 x hours

How to use the Alcohol BAC Timeline Calculator

  1. 1Enter sex, weight, number of standard drinks and time elapsed since your first drink.
  2. 2The Widmark formula is a population estimate and can be significantly off for a given individual due to metabolism, food intake and drink strength.
  3. 3Never use this to decide whether it is safe to drive — BAC estimates are not reliable enough for that decision. If in doubt, do not drive.

Worked example

Using the values the calculator loads with:

Inputs

  • SexMale
  • Weight80 kg
  • Standard drinks (14g alcohol each)4
  • Hours since first drink2 hours

Results

  • Estimated BAC0.073%
  • Hours until sober (BAC 0)4.9
  • Legal driving limit noteCommon limit is 0.05-0.08% — check your local law

Frequently asked questions

Is this accurate enough to decide if I can drive?

No — treat it purely as educational; individual variation is large and actual testing is the only reliable measure.

Does food affect BAC?

Yes, food slows alcohol absorption and can lower peak BAC, which this simple formula does not fully capture.

About this calculator

Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.