When you go to bed, how many cups of coffee are still in your system?

When did you have coffee?

No coffee counted today

Planned bedtime

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FAQ

How does this work?

We use the coffee times, cup count, and planned bedtime you enter to estimate how much caffeine may still be in your system before sleep.

Caffeine usually starts to kick in about 15-45 minutes after you drink it, and its half-life is roughly 5-6 hours. In plain terms: after 5-6 hours, around half of it may still be hanging around.

To make the number easier to understand, we turn the estimate into "cups of coffee left." It's not a lab test, just a small tool for reading the general trend.

How to read "cups left"

Around 0.2 cups left usually means most of the caffeine has already faded.

Around 0.5 cups left means there's still a noticeable little trace before bed.

Above 0.8 cups left is like having most of a cup's caffeine still with you at bedtime. If you're sensitive to caffeine, that could already be enough to affect sleep.

Let your own body be the baseline

The same cup can let one person sleep just fine and leave another staring at the ceiling at 2 AM.

Coffee strength, cup size, your body, schedule, stress, medication, pregnancy, or breastfeeding can all change how it actually feels.

Use this as a bedtime reference, not medical advice. If you often have heart palpitations, anxiety, insomnia, or you're taking medication, play it more conservatively and consider talking to a professional.

Where did coffee come from?

Coffee has been traveling for centuries.

Wild coffee plants are commonly traced back to Ethiopia. Later, coffee crossed the Red Sea to Yemen, where people began growing it, brewing it, and turning it into a culture.

From the Arab world, it moved into Europe. Through ports, caravans, and coffeehouses, it slowly became the first cup of the day for many people.

A cup of coffee has come a long way

A coffee bean is actually the seed of a coffee tree.

It sprouts in soil, is cared for, transplanted, and grown into a tree. Only years later does it produce coffee cherries. The ripe fruit is picked, processed, dried, roasted, ground, and finally becomes the cup in your hand.

So today's coffee is more than a short burst of alertness. It has passed through land, time, weather, farmers, roasters, and many hands.

Of course, by bedtime, it should also know how to behave: when it's time to clock out, no overtime.