What Time Should I Go to Bed?

It is the question everyone types into a search box at 11pm, usually while already tired. The honest answer is that there is no single bedtime that works for everyone, because the right time depends on when you have to wake up, how much sleep you need, and how long it takes you to fall asleep. But once you know those three numbers, the answer becomes simple arithmetic.

Start from your wake time, not your bedtime

Most people pick a bedtime first and hope the morning works out. It works better the other way around. Your wake time is usually fixed by work, school, or family, so it is the anchor. Count backward from it in full sleep cycles and you get bedtimes that let you wake at the end of a cycle, when sleep is lightest and grogginess is mildest.

A sleep cycle averages about 90 minutes, though real cycles range roughly from 70 to 120 minutes and change across the night. Five cycles give you 7.5 hours of sleep, six cycles give you 9 hours. For most adults, one of those two totals is the sweet spot.

Bedtimes for common wake times

The table below assumes 15 minutes to fall asleep, which is typical for healthy sleepers. If you usually take longer, shift every bedtime earlier by the difference.

For any other wake time, use the bedtime calculator. Enter your wake time and it works out the same cycle-aligned options for you.

How many hours do you actually need?

The American Academy of Sleep Medicine recommends that adults regularly get 7 or more hours of sleep a night, and the National Sleep Foundation suggests 7 to 9 hours for adults aged 18 to 64. Teenagers need more, around 8 to 10 hours, and school age children need 9 to 11. If you consistently feel alert on 7.5 hours but foggy on 6, that is useful data, not a failure of willpower. Sleep need varies between people, and it also varies with age, illness, and how much sleep debt you are carrying.

A practical test: if you wake without an alarm on free days and feel rested, note how long you slept. Do that for a week and a pattern emerges. That number, rounded to the nearest cycle, is a better bedtime target than any generic chart.

The 15 minutes most people forget

Bedtime is not the same as sleep time. Most people need roughly 10 to 20 minutes to fall asleep, and every calculator on this site adds that gap before counting cycles. If you climb into bed at 11:15pm expecting to be asleep instantly, your cycles start later than planned and your alarm lands mid-cycle. Be in bed a little before your target, lights low, screens down, and let the 15 minutes do their work.

When a fixed bedtime beats a perfect one

A cycle-perfect bedtime that changes every night is worth less than a slightly imperfect bedtime you keep every night. Your internal clock runs on regularity: the same bedtime and wake time, weekends included as far as life allows, trains your body to get sleepy at the right hour and to wake before the alarm. If your schedule only allows one of the two, keep the wake time fixed. It is the stronger anchor.

If you work nights or rotating shifts, the same logic applies to your daytime sleep window. The shift work sleep planner works out sleep windows that fit around your shifts instead of fighting them.

This guide gives planning estimates based on average sleep cycle timing. It is not medical advice and cannot diagnose sleep problems. If poor sleep persists, talk to a clinician.

Frequently asked questions