Plot how much caffeine is still in your system at bedtime, drink by drink
Your day
- mg
- mg
5 h
Around 5 hours for most adults — slower on some medication, faster for regular coffee drinkers.
Caffeine through the day
30 mg
Borderlinestill circulating at 23:00- Caffeine in your system
- 50 mg sleep threshold
- Drinks
- At bedtime
- 30 mg
- Peak load
- 104 mg
- Total intake
- 158 mg
- Drops below 50 mg
- 19:20
Estimates only, based on first-order decay from typical serving sizes. Not medical advice.
Caffeine leaves your body on a half-life of roughly five hours, which is why a 4pm espresso is still with you at midnight. Add each drink with its time and dose, set your bedtime, and the chart plots your caffeine load through the day — the peak, what is left when you go to bed, and the moment you drop below the 50 mg mark that still disturbs sleep for most people. Adjust the half-life if you metabolise caffeine faster or slower than average.
How to Use
- 1Add each drink from the presets, or type the milligrams directly
- 2Set the time of each drink and your bedtime
- 3Adjust the half-life slider if you know you clear caffeine faster or slower
- 4Read the curve, then download the card or copy the summary and link