GoodSleep › Alcohol Sleep Clearance Calculator

Alcohol Bedtime
Clearance Calculator

Time your drinks to protect your sleep cycle. Calculate how long it takes for alcohol to exit your bloodstream and prevent midnight wakefulness.

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Calculator Inputs

160 lbs
🍺 Beer (12oz, 5%)
0
🍷 Wine (5oz, 12%)
0
🥃 Spirit/Shot (1.5oz, 40%)
0
2 Hours
Estimated Clearance Time
Clear in 2.5 Hours
REM Sleep Disruption: Mild
Your body requires time to metabolize alcohol. Drinking too close to bedtime blocks REM sleep, elevates heart rate, and causes micro-arousals during the second half of the night.
💤 Sleep Verdict: Your system is expected to be clear before bedtime. You will likely experience minimal sleep disturbance.
BAC Metabolism & Bedtime Alignment
0.12% 0.08% 0.04% 0.00% Hours Since Drinking Started Bedtime
Sleep Science Tip: Even if your BAC returns to 0% before you sleep, aldehydes (byproducts of alcohol metabolism) can cause mild dehydration and sleep fragmentation. Drink a full glass of water with electrolytes before going to bed.

The Physiology of Alcohol and Sleep

Why alcohol acts as a sleeping aid initially, but destroys sleep quality later.

1. REM Suppression

Alcohol is a potent central nervous system depressant that increases GABA activity, helping you fall asleep fast. However, it severely suppresses REM (Rapid Eye Movement) sleep in the first half of the night, affecting cognitive function and memory consolidation.

2. Autonomic Disruption

During normal sleep, your parasympathetic nervous system dominates, lowering your heart rate and allowing tissue repair. Alcohol keeps your sympathetic nervous system active, resulting in a higher sleeping heart rate and reduced heart rate variability (HRV).

3. Midnight Rebound

As your liver clears the alcohol (usually at a rate of 0.015% BAC per hour), your body experiences a withdrawal-like stimulant rebound. This causes frequent micro-arousals, nighttime sweating, and early morning wakefulness, leaving you exhausted.