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What Time Should I Stop Caffeine for a 10 PM Bedtime?

  1. 6-hour cutoff

    Last caffeine by

    16:00 24h

    6 hoursbefore bed

    A planning rule, not a guarantee.

  2. More cautious · 8 hours

    14:00 24h

    8 hoursbefore bed

For a 10:00 PM (22:00) bedtime, a common planning cutoff for caffeine is 4:00 PM (16:00), 6 hours before bed. A more cautious cutoff is 2:00 PM (14:00), 8 hours before. Neither is a guarantee: how caffeine affects your sleep depends on how much you have and how sensitive you are.

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My bedtime is

22:00 in 24-hour time

Your caffeine cutoffs

    Cutoffs are planning rules based on research averages. Caffeine sensitivity and dose vary, so neither time is a guarantee.

    How the 10 PM cutoffs are worked out

    Both cutoffs count back from your bedtime. For 10:00 PM (22:00), 6 hours earlier is 4:00 PM (16:00) and 8 hours earlier is 2:00 PM (14:00).

    The 6-hour figure comes from a well-known sleep study in which a large dose of caffeine taken 6 hours before bed still cut total sleep by more than an hour. The 8-hour cutoff builds in more margin. A 2023 review of the research suggested that, on average, a typical cup of coffee should be finished nearly 9 hours before bed to avoid losing sleep, and that stronger doses need even longer. So even the cautious cutoff is a planning rule, not a guarantee.

    Caffeine cutoffs around a 10:00 PM bedtime
    Bedtime6-hour cutoff8-hour cutoff
    9:00 PM21:003:00 PM15:001:00 PM13:00
    9:30 PM21:303:30 PM15:301:30 PM13:30
    10:00 PM22:004:00 PM16:002:00 PM14:00
    10:30 PM22:304:30 PM16:302:30 PM14:30
    11:00 PM23:005:00 PM17:003:00 PM15:00

    Why caffeine affects people differently

    Caffeine blocks adenosine, a chemical that builds up while you’re awake and helps make you sleepy. Your body clears caffeine gradually over several hours, and how fast varies a lot from person to person.

    • Dose: a double espresso or an energy drink carries far more caffeine than a cup of tea.
    • Sensitivity: genetics, age, pregnancy, some medicines and liver health all change how long caffeine stays in your system.
    • Habit: regular drinkers may feel less of a buzz, but caffeine can still make their sleep lighter and shorter.

    You can fall asleep easily and still have lighter, more broken sleep after late caffeine, so “it doesn’t affect me” isn’t always the full picture.

    How much caffeine is in common drinks

    Amounts vary by brand, size and how a drink is made, but as a rough guide from the U.S. Food and Drug Administration:

    • 8 oz (240 ml) brewed coffee: about 80–100 mg
    • 8 oz black or green tea: about 30–50 mg
    • 12 oz (355 ml) cola: about 30–40 mg
    • 8 oz energy drink: about 40–250 mg
    • 8 oz decaf coffee: about 2–15 mg

    Chocolate, some pain relievers and pre-workout supplements contain caffeine too. The FDA considers up to 400 mg a day generally safe for most healthy adults, but that’s a daily limit, not a guide to timing.

    Planning caffeine around a 10 PM bedtime

    If you’re up at 6:00 or 7:00 AM, a 2:00 PM cutoff still leaves most of the working day for coffee. Many people find it easiest to keep caffeine to the morning and early afternoon, then switch to decaf, herbal tea or water after lunch.

    Watch for later caffeine you might not count: a cola with dinner, iced tea, a chocolate dessert, or a pre-workout drink before an evening gym session. If you still struggle to fall asleep at 10:00 PM, try moving your cutoff earlier for a week and see whether it helps.

    More answers

    Frequently asked questions

    Can I drink coffee at 4 PM if I go to bed at 10 PM?

    A 4:00 PM (16:00) coffee sits right at the 6-hour cutoff. Some people sleep fine after it; others, especially after a strong coffee or if they’re sensitive to caffeine, may find their sleep lighter or shorter. Moving it to 2:00 PM (14:00) or switching to decaf gives more margin.

    Does decaf coffee count?

    Decaf still contains a little caffeine, usually about 2–15 mg per 8 oz cup, compared with roughly 80–100 mg in regular brewed coffee. For most people, a cup of decaf in the afternoon is unlikely to matter much.

    I had caffeine too late. What should I do?

    Stick to your usual routine: wind down as normal, go to bed when you feel sleepy, and keep your usual wake-up time the next morning. Avoid more caffeine that evening, and try an earlier cutoff the next day.

    • Bedtime calculator

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    Sources

    1. Drake C, Roehrs T, Shambroom J, Roth T. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. Journal of Clinical Sleep Medicine, 2013;9(11):1195–1200. doi:10.5664/jcsm.3170.
    2. Gardiner C, Weakley J, Burke LM, et al. The effect of caffeine on subsequent sleep: A systematic review and meta-analysis. Sleep Medicine Reviews, 2023;69:101764. doi:10.1016/j.smrv.2023.101764.
    3. U.S. Food and Drug Administration. Spilling the Beans: How Much Caffeine Is Too Much?
    4. National Institute of Neurological Disorders and Stroke. Brain Basics: Understanding Sleep.

    When to seek help

    Talk to a doctor or pharmacist if you:

    • rely on caffeine to get through most days, or feel shaky, anxious or notice a racing heart after it;
    • still struggle to fall or stay asleep after moving caffeine earlier in the day;
    • are pregnant, breastfeeding, have a heart condition or take regular medication, and want to know how much caffeine is right for you;
    • are unsure how much caffeine is suitable for a child or teenager.