Caffeine calculator
Add up the caffeine from the coffee, tea, soda, energy drinks and chocolate you have in a day, compare it with the recommended limit and see how much is still in your body at bedtime.
How to useHow much caffeine you have
Approximate average values. People with high blood pressure, arrhythmia, anxiety or on medication should follow their doctor’s advice.
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Caffeine calculator: what it is for
Brewed coffee, espresso, tea, cola, energy drinks, chocolate and pre-workout have very different amounts of caffeine. Check what you had and when, and the calculator adds up the day's total, compares it with the 400 mg limit from the FDA and EFSA (or 200 mg in pregnancy) and estimates, with a half-life of about 5 hours, how much will still be in your body at bedtime.
Everything is calculated in your browser: no health data is sent or stored on a server.
How to use
- Enter the amount of each drink and the time.
- Choose the profile and adjust the half-life if you want.
- See the total, the percentage of the limit and what's left at bedtime.
When to use it
- Keep track of coffee at work.
- Pregnant women who want to stay under 200 mg.
- Understand why afternoon coffee hurts your sleep.
Frequently asked questions
What is the daily caffeine limit?
For healthy adults, the FDA and the European EFSA consider up to about 400 mg a day safe, about 4 cups of brewed coffee. For pregnant women, the limit recommended by the American College of Obstetricians and Gynecologists and by EFSA is 200 mg a day.
How long does caffeine stay in the body?
Caffeine's half-life in adults is about 5 hours, but it varies a lot between people, from 2 to more than 9 hours. That means that 5 hours after a coffee, half the caffeine is still there. The calculator estimates how much is left at bedtime.
Are the values for each drink exact?
No. Caffeine varies with the bean, the brewing and the brand. The tool uses approximate averages; you can adjust each item according to the label.
Is it really free?
Yes, 100% free. No sign-up, no subscription and no usage limits. All Tools123 tools are free and run right in your browser.