Caffeine Half-Life Calculator
Track how caffeine metabolizes in your body and find the best time to stop drinking coffee for better sleep.
Caffeine Intake
Quick Select:
Half-life: 5 hours
Caffeine at Bedtime
13.6 mg
14.4% remaining | Effect: Minimal
Safe Sleep Time
01:00 PM
Under 50mg
Latest Coffee Time
05:00 PM
For your bedtime
Caffeine Decay Timeline
08:00 AM
95mg
01:00 PM
48mg
06:00 PM
24mg
11:00 PM
12mg
04:00 AM
6mg
Hourly Caffeine Levels
08:00 AM
95.0mg
09:00 AM
82.7mg
10:00 AM
72.0mg
11:00 AM
62.7mg
12:00 PM
54.6mg
01:00 PM
47.5mg
02:00 PM
41.4mg
04:00 PM
31.3mg
06:00 PM
23.8mg
08:00 PM
18.0mg
10:00 PM
13.6mg
12:00 AM
10.3mg
Sleep & Caffeine Tips
- Stop caffeine 6-8 hours before bedtime
- Caffeine blocks adenosine (sleepiness signal)
- Genetics affect how fast you metabolize caffeine
- Limit intake to 400mg/day (about 4 cups)
- Caffeine has a half-life of 3-7 hours in most adults
Understanding Caffeine Half-Life
What is Half-Life?
Half-life is the time it takes for half of the caffeine to be eliminated from your body. The average half-life is 5 hours, but it can range from 3-7 hours depending on genetics, age, liver function, and other factors.
Factors That Affect Caffeine Metabolism
- Pregnancy (half-life can double or triple)
- Smoking (speeds up metabolism)
- Oral contraceptives (slows metabolism)
- Liver conditions
- Certain medications