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Caffeine Calculator
Current caffeine level, safe sleep time, and daily limit — based on your drinks and caffeine half-life.
Drinks consumed today
Current caffeine level
95mg
Total intake today
95mg
Safe to sleep from
05:02FDA daily limit (400 mg)
24%Within FDA daily limit
Caffeine decay over time
Caffeine half-life: ~5 hours
Now
95
+2h
72
+4h
54
+6h
41
+8h
31
< 100 mg — safe to sleep
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Caffeine Calculator: How Long Until You Can Sleep? →Caffeine has a half-life of ~5 hours. Calculate your current caffeine level and find out when you can safely fall asleep tonight.