How late is too late for coffee?

Updated 6 October 2026.

The coffee at 3pm makes sense at 3pm. You’ve got work left, your concentration’s wandering and bed feels a long way off.

At 11pm, it can feel like a less successful decision.

Start by leaving at least six hours between your last caffeinated drink and bedtime. If sleep is still difficult, try an earlier cut-off or a smaller amount: both timing and dose matter.

What time should you stop drinking coffee?

The NHS’s insomnia guidance advises avoiding tea and coffee for at least six hours before bed. For an 11pm bedtime, that means finishing by 5pm.

Treat that as a starting point. If you’re regularly awake longer than you’d like, try moving your last coffee to lunchtime and see whether your nights change.

A fixed “no coffee after 2pm” rule won’t fit every schedule. Count back from when you actually go to bed.

How long does caffeine stay in your system?

Caffeine takes hours to clear, and the speed varies considerably between people.

The European Food Safety Authority’s caffeine explainer, published in May 2015, gives an average half-life of about four hours in healthy adults, with a range of two to eight hours. Half-life means the time it takes your body to eliminate half the caffeine.

For someone with a four-hour half-life, a 100 mg dose at 3pm would leave roughly 50 mg at 7pm and 25 mg at 11pm. That’s an illustration of the calculation; your own clearance could be faster or slower.

The noticeable lift may fade while caffeine is still in your body.

Does the amount matter as much as the time?

The amount matters too: a large dose can affect sleep much earlier in the day.

In a randomised trial by Carissa Gardiner and colleagues, first published on 8 October 2024, the analysis included 23 healthy men recruited within an 18–40 age range. They received their usual daily caffeine amount in a capsule within an hour of waking, plus a test dose or placebo later.

The 100 mg test dose showed no statistically significant sleep effects at four, eight or twelve hours before bed. The 400 mg dose affected aspects of sleep even twelve hours beforehand. Neither dose was tested at bedtime.

Six hours remains the NHS’s general starting point. Smaller doses may have less impact, but individual responses vary and this small trial doesn’t establish a cut-off for everyone.

Using the EFSA table below, 100 mg is close to one 200 ml filter coffee. A 400 mg dose is roughly four to five of those coffees taken together. That comparison gives you a sense of scale; the trial didn’t test four coffees spread across the day.

Can coffee affect sleep even if you fall asleep easily?

It can affect what happens after you’ve fallen asleep too.

In the Gardiner trial, 400 mg affected measured sleep at eight and twelve hours before bed without a statistically significant fall in reported sleep quality at those times. Feeling that you slept well may miss some changes.

If being worn out and feeling ready for sleep seem like two different things, our tired-but-wired article explains that experience.

Do tea and energy drinks count?

Tea and energy drinks contain caffeine, so include them when deciding where to put your cut-off.

Here are EFSA’s approximate amounts. Strength, preparation and serving size can change the figures substantially.

Green tea also contains caffeine. For packaged drinks, check the amount in the whole can or bottle, rather than assuming the number on the label covers all of it.

If you use a caffeinated pre-workout or supplement, include that as well.

If you’re pregnant, the NHS advises no more than 200 mg a day from all sources.

Is decaf a useful evening alternative?

Decaf is a useful swap when you want to keep the drink with much less caffeine.

It still contains some. The US Food and Drug Administration’s consumer guidance puts a typical 240 ml cup of decaf coffee at roughly 2–15 mg.

If you’re particularly sensitive, choose something labelled caffeine-free. Swapping your late coffee for ordinary black or green tea won’t remove caffeine from the evening.

Do you need to give up coffee to sleep better?

You can start by changing the late drink, without removing coffee from your whole day.

Try this for a week or two: keep your morning coffee, replace the afternoon or evening top-up with decaf, and keep your usual wake time. Make a brief note each morning of how you slept and how you feel.

If you’re cutting your total intake substantially, reduce it gradually. The Sleep Charity recommends cutting down gradually, as stopping suddenly can cause headaches and sleep problems.

After a poor night, it’s tempting to keep topping up. Our guide to the day after a bad night’s sleep covers the other ways to make that day more manageable.

What if changing your coffee doesn’t help?

Caffeine may be one contributor among several. Worry, sleep timing and the transition out of work can also need attention.

Try our guide to winding down before bed for that part of the evening. If sleep problems continue despite changes, have lasted for months or make daily life hard to cope with, the NHS advises seeing your GP.

For tomorrow, start with the coffee you usually have latest. Make that one earlier or decaf.

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