SafeBAC CalculatorInformational BAC Tool

BAC Time to Zero Calculator

Use this tool to better understand why sleeping, coffee, or a short break cannot instantly make you sober enough to drive.

Estimate time for your BAC to fall

Enter an estimated current BAC value to see a rough time range for your BAC to fall toward zero and below a commonly cited legal limit in your region.

You can enter a value from this or another BAC calculator, or from a device reading, if available. All values are treated as approximate.

Used only to compare your estimated BAC with commonly cited drink-driving limits. Always check current official laws in your area.

Enter an approximate BAC value and choose your region to see a rough time range. Everyone processes alcohol differently, so treat the results as educational only.

What does BAC time to zero mean?

BAC time to zero is an estimate of how long it might take for your body to metabolize alcohol so that your measured blood alcohol concentration returns toward 0.00%. It is always an approximation because metabolism varies widely between people and even for the same person on different days.

What affects how fast BAC falls?

Typical BAC elimination rates are often described as roughly 0.010–0.020% BAC per hour, but your actual rate can be slower or faster. Genetics, liver health, medications, food, body composition, drinking pattern, and many other factors all influence how quickly your BAC changes.

Why quick‑fix sobriety myths are dangerous

Coffee, cold showers, fresh air, and similar tricks may make you feel more awake, but they do not significantly speed up the elimination of alcohol from your body. Only time allows your BAC to fall. You can still be impaired or over the legal limit even if you feel more alert.

Why you should not drive while waiting

Even if an estimate suggests that your BAC might drop below a legal limit at a certain time, there is no guarantee that you will no longer be impaired. The safest option after drinking is always to arrange another way home instead of driving yourself.

BAC time to zero FAQ

No. The tool can only give a very rough estimate based on typical elimination rates. Your actual BAC may still be higher or lower than the estimate at any moment. Only professional testing can measure your real BAC.
Not in any meaningful or safe way. Time is the key factor. Coffee, cold showers, or exercise may make you feel different, but they do not reliably speed up the elimination of alcohol from your body.
No. You must never use this or any BAC calculator to decide whether it is safe or legal to drive. If you have been drinking, the safest choice is always not to drive.