Caffeine Calculator - Daily Intake, Limit & Caffeine Left at Bedtime
Caffeine Calculator
Add up your caffeine and see how much is left when you go to bed
Daily Total
Choose from common drinks with typical caffeine amounts, or enter your own, and see the day's total against your limit.
Bedtime Level
Each drink fades with a half-life, so the calculator adds up what is left at bedtime from every drink you had earlier.
When It Clears
See the clock time at which your caffeine level drops below a cut-off you choose.
Full Privacy
Everything is calculated in your browser.
How Much Caffeine Is Too Much?
For most healthy adults, up to about 400 mg a day, roughly four cups of brewed coffee, is not generally associated with harm. Health authorities suggest a lower limit of about 200 mg for pregnancy and breastfeeding, and teenagers are usually advised to keep well below adult amounts. Amounts in drinks vary widely by brand and brew, so the figures here are typical values, not exact ones.
Caffeine has a half-life of about five hours in many adults, so a coffee at 3 pm can still leave a quarter of its caffeine at 11 pm. The half-life varies with genetics, smoking, medicines, liver health and pregnancy, so adjust it if you know yours. This is general information, not medical advice. If caffeine gives you palpitations, anxiety or sleep trouble, or you have a heart condition, speak to a doctor.
Key Takeaways
- Adjustable: Change the limit, half-life, bedtime and sleep cut-off to suit you.
- Time-aware: Caffeine taken after bedtime is kept out of the bedtime level.
- Information only: Not a diagnosis or medical advice.