Time to Sober Up Calculator
Work out a rough estimate of how long it takes for your blood alcohol content to reach zero, based on an average elimination rate.
How to use the time to sober up calculator
- Enter your estimated blood alcohol content right now, for example from a breathalyzer or blood alcohol calculator.
- The calculator works out how many hours it takes for your blood alcohol content to reach 0.0‰ at an average elimination rate.
- See the estimated time you'd be back to zero — but remember this is only a rough estimate.
How the time to sober up is calculated
The body breaks down alcohol at a relatively steady pace, regardless of how much you've had to drink. The calculator uses a commonly cited average value of 0.15 per mille per hour:
With a blood alcohol content of 0.8‰, this calculation gives roughly 0.8 ÷ 0.15 ≈ 5.3 hours until it reaches zero. In practice, this figure varies from person to person and can be affected by body weight, sex, food in the stomach, medication and general health.
Frequently asked questions
Can I trust that I'm sober when the calculator says so?
No. This is only a rough mathematical average estimate. Individual variation is large, and the actual elimination rate can be both faster and slower than 0.15‰/hour. Never use this calculator to decide whether it's safe to drive.
Why is 0.15 per mille per hour used?
0.15‰/hour is a widely used average value for how quickly the body breaks down alcohol. The actual elimination rate normally varies between about 0.10 and 0.20‰/hour depending on the person.
Does coffee, a shower or food help you sober up faster?
No. Neither coffee, a cold shower, fresh air nor food speeds up how fast alcohol is broken down. Only time brings blood alcohol content down.