Caffeine Calculator
Calculate your caffeine intake, track how long it stays in your system, and know when it's safe to sleep.
Caffeine Intake
mg
hours
Enter 0 if you just consumed it
Total Caffeine Consumed
190 mg
Safe Level
☕Current in System
190 mg
⏱️Half-Life
5.5 hrs
📊% of Daily Limit
48%
⚖️Per Body Weight
2.7 mg/kg
Sleep Recommendation
Wait approximately 10.6 hours for caffeine to drop below 50mg for better sleep quality.
Potential Effects
- Increased alertness
Common Caffeine Sources
Espresso (1 shot)63 mg
Brewed Coffee (8 oz)95 mg
Drip Coffee (8 oz)145 mg
Cold Brew (8 oz)200 mg
Black Tea (8 oz)47 mg
Green Tea (8 oz)28 mg
Energy Drink (8 oz)80 mg
Red Bull (8.4 oz)80 mg
Monster (16 oz)160 mg
Recommended daily limit: 400mg for healthy adults. Pregnant women should limit to 200mg.