Caffeine calculator
How much caffeine is still in you?
Enter what you’ve had to drink today and when. The calculator shows you how much of it is still in your body at bedtime.
The curve shows how much caffeine is in your body over the day. The horizontal line marks 50 mg: above it, most people find it noticeably harder to fall asleep. The vertical line is your bedtime.
* This assessment applies to average, healthy adults. If you are pregnant, breastfeeding, taking medication or sensitive to caffeine, you break it down much more slowly and should not rely on these values. During pregnancy, professional bodies recommend no more than 200 mg per day. If you have health questions, your doctor is the right person to ask.
A quick word on half-life.
Caffeine is broken down in the liver, with a half-life of about five hours. That means: of a double espresso at 2 pm with 126 mg, around 63 mg is still left at 7 pm and still about 25 mg at midnight. That is exactly what the curve above calculates, for each drink separately and then added up.
How much half-lives really tell you
The actual half-life varies between about three and ten hours. It depends on a liver enzyme whose activity is set by your genes. Smoking speeds up the breakdown considerably, while hormonal contraception and pregnancy slow it down a lot. So if you can drink an espresso late in the evening without any trouble, you're not imagining it.
And if it still has to be a coffee?
That's what decaf is for. Our Decaf Guji Natural from Ethiopia has around 3 mg per espresso instead of 63 mg, yet tastes like a proper specialty coffee and not like a stopgap.
The calculator is a guide, not medical advice. The values per drink are averages and vary considerably depending on bean, roast and preparation. If you take medication, are pregnant or have health questions about caffeine, talk to your doctor.