Your afternoon coffee has a way of staying longer than you invited it to. The cup is empty, the working day is over and you’re ready for bed. Some of that caffeine may still be hanging around.
Understanding how long caffeine stays in your system can change the way you look at your daily coffees. The number of cups tells you part of the story. When you drink them matters, too.
If you’d like to see what your routine could look like, try our free caffeine calculator. It helps you estimate how much caffeine may still be in your system at bedtime.
How long does caffeine take to wear off?
Caffeine leaves your body gradually. Its “half-life” is the time it takes to clear half a dose. The European Food Safety Authority reports an average of around four hours in healthy adults, with a range of two to eight hours. Medication, pregnancy and liver health can affect this timing.
That means one half-life doesn’t take you back to zero. Half remains, then half of that, and so on. There isn’t a single hour when everyone’s coffee neatly switches off.
What could be left at bedtime?
Let’s use a five-hour half-life as an illustrative assumption. Imagine a drink containing 100mg of caffeine at 3pm:
| Time | Estimated caffeine remaining from that drink |
|---|---|
| 3pm | 100mg starting dose |
| 8pm | 50mg |
| 10pm | 38mg |
| 1am | 25mg |
These are calculated estimates using a simplified model that assumes immediate absorption. They aren’t measurements of your body or predictions of how well you’ll sleep.
The example also covers only one drink. Add an earlier coffee and some caffeine from that cup may remain, too. To estimate a whole day, each drink needs its own dose and time in the calculation.
That’s why it’s useful to put your routine into the calculator. Try an earlier last coffee or a smaller dose and compare the estimates.
How much caffeine is too much?
EFSA considers up to 400mg spread throughout the day to raise no safety concerns for most healthy, non-pregnant adults. That is a population guideline, not a target or a guarantee of uninterrupted sleep. It also notes that 100mg close to bedtime can affect sleep in some adults.
Your own response matters. Jitters, anxiety, stomach upset and disrupted sleep can be signs of too much caffeine. If you’re experiencing symptoms, or you’re pregnant, breastfeeding or taking medication that could interact with caffeine, talk to your healthcare professional about your intake.
Why counting coffees can be misleading
“Two coffees” isn’t a precise caffeine dose. Beans, preparation and serving size all influence the amount in the cup. EFSA uses 80mg for a 60mL espresso as a reference, but explicitly notes that amounts vary. Your café order may contain more or less.
For a more useful estimate, check product information where available and include other sources, such as tea, energy drinks and pre-workout. A calculator is only as accurate as the amounts you enter.
Start with one change to your routine
You don’t need to decide the fate of every future flat white today. Start by looking at the coffee you reach for latest in the day. Would you enjoy something else in that same mug, during that same ten-minute break?
If you decide to reduce caffeine, make the change gradually. The FDA recommends cutting back over time because withdrawal can be unpleasant. Decaf is another option, although it still contains some caffeine.
Keep your ritual. Change what’s in your cup.
For many of us, the best part of a coffee is the moment around it. Putting the kettle on. Stepping away from the screen. Holding something warm before the day asks for anything else.
Earthrise gives you another way to enjoy that moment. Our Original Blend is a coffee alternative with cacao, functional mushrooms and warming spices. Expect a chocolate-and-spice flavour rather than a replica of roasted coffee. It contains caffeine from cacao, so it still counts towards your daily intake.
Ready to try a different cup? The Starter Kit includes 30 serves of your chosen blend, a self-stirring mug and a spoon. Choose Original Blend to start a new morning or afternoon ritual.
