Caffeine Half-Life Calculator
Track when caffeine clears your system for better sleep
Coffee
95mg • 8oz
Espresso
64mg • 1oz
Black Tea
47mg • 8oz
Energy Drink
80mg • 8.4oz
Caffeine clears below 10mg by:
6:00 PM
Sleep impact until: 7:30 PM
Caffeine Consumed:
95 mg
Consumed at:
2:00 PM
Your Half-Life:
5 hours
Just Consumed
50% Cleared
Mostly Cleared
Clearance Timeline
2:00 PM
Consumed 95mg caffeine
7:00 PM
47mg – May affect sleep
10:00 PM
12mg – Mostly cleared
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Frequently Asked Questions
How long does 200mg of caffeine stay in your system?
With an average 5-hour half-life, 200mg of caffeine takes about 15 hours to clear below 10mg. Use our caffeine Half-Life calculator for personalized results.
What is the half-life of caffeine?
The average caffeine half-life is 5 hours, but ranges from 3 hours (fast metabolizers) to 10+ hours (slow metabolizers).
When should I stop drinking coffee before bed?
Most people should stop caffeine 6-8 hours before bedtime. Our caffeine half-life calculator gives you a personalized time based on your consumption and metabolism.