Clinical Accuracy Verified
Data verified on 2026-04-20 Reviewed by Michael R. Chen, CPA, CFP®
Caffeine Half-Life Calculator
Find out when your coffee leaves your system so you can sleep.
1 Protocol
Hours
:
Mins
Clearance Timeline
After 5 Hours
7:00 PM
100 mg left
After 10 Hours
12:00 AM
50 mg left
Safe to Sleep
12:00 AM
< 50 mg
The 5-Hour Rule
The average half-life of caffeine is 5-6 hours.- If you drink 200mg at 4 PM (Double Espresso) ->
- At 9 PM, you still have 100mg in your blood.
- At 2 AM, you still have 50mg.
☕ Caffeine Metabolism Timeline (200mg Dose)
| Time Elapsed | Caffeine in System | Physiological Effect | | :--- | :--- | :--- | | 0 mins | 0 mg | Absorption begins | | 45 mins | 200 mg (Peak) | Max Alertness / Jitters | | 3 Hours | 130 mg | Focus remains high | | 5 Hours (Half-Life)** | **100 mg | Effect fades, but still present | | 10 Hours | 50 mg | Can inhibit deep sleep | | 12 Hours | 25 mg | Trace amounts |Strategy
Stop caffeine intake 8-10 hours before bed to ensure deep sleep quality (adenosine receptor availability).Results Caffeine Half-Life Calculator
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