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Estimate how many hours until blood alcohol concentration (BAC) falls to a target—usually 0.00 g/dL (sober), or teaching thresholds like 0.05 or 0.08 g/dL. Uses a linear elimination model (about 0.012–0.018 g/dL per hour) with slow, typical, and fast presets. Start from a known breath or blood BAC, or estimate drinks first with our BAC calculator. Not for legal or forensic use.
Last updated: June 4, 2026
U.S. labels often read as “0.08 BAC” meaning 0.08 g/dL. If you only have a breath estimate, treat it as uncertain.
Time until at or below 0.00 g/dL
5 h 20 min
Range (0.012–0.018 g/dL/h): 4 h 26 min – 6 h 40 min
Time until ~0.00 g/dL at this preset
5 h 20 min
Range: 4 h 26 min – 6 h 40 min
Preset slope used: 0.015 g/dL per hour.
0.08 → 0.00 g/dL
5 h 20 min
Range 4 h 26 min – 6 h 40 min
0.10 → 0.00
6 h 40 min
0.12 → 0.08 g/dL
2 h 40 min
Under US per se limit (not “safe to drive”)
0.15 → 0.00
10 h
After absorption has peaked:
hours ≈ (BACcurrent − BACtarget) ÷ β
β = elimination rate in g/dL per hour. Time to ~0: hours ≈ BAC ÷ β.
| Preset | β (g/dL/h) | Use |
|---|---|---|
| Conservative (slow) | 0.012 g/dL/h | Longer clearance — use for cautious planning |
| Typical | 0.015 g/dL/h | Common textbook average |
| Fast | 0.018 g/dL/h | Shorter clearance — still not guaranteed for you |
Typical slope 0.015 g/dL/h; range uses fast (0.018) to slow (0.012) presets.
| Starting BAC | Typical time to ~0 | Fast–slow range |
|---|---|---|
| 0.08 g/dL | 5 h 20 min | 4 h 27 min – 6 h 40 min |
| 0.10 g/dL | 6 h 40 min | 5 h 33 min – 8 h 20 min |
| 0.12 g/dL | 8 h | 6 h 40 min – 10 h |
| 0.15 g/dL | 10 h | 8 h 20 min – 12 h 30 min |
Rising BAC while alcohol is still absorbing (you can be more impaired than this predicts mid-drinking).
Chronic heavy use, liver disease, or drug interactions that change metabolism.
Breath-test error, mouth alcohol, or legal procedures beyond a number you type.
Never drive impaired. These hours are estimates only. Alcohol poisoning requires emergency care—call 911 or your local emergency number.
For driver education and harm-reduction planning
Suggested hashtags: #BAC #AlcoholEducation #Safety #Calculator