Medical disclaimer

This calculator gives general estimates based on average 90-minute sleep cycles. It isn’t medical advice. If you have ongoing trouble sleeping, loud snoring, or daytime sleepiness, talk to a doctor.

This article is general information, not medical advice.

What our calculators do

The calculators use average figures, such as a 90-minute sleep cycle and a typical time to fall asleep, to estimate bedtimes, wake-up times, nap alarms, a weekly sleep shortfall and the caffeine that may remain at bedtime. Real sleep varies from person to person and night to night: cycles can be roughly 70 to 120 minutes [1]. The results are estimates, not measurements, and they can’t tell you whether your sleep is healthy.

What we don’t do

• We don’t diagnose sleep disorders or any other condition.
• We don’t recommend treatments, medicines, supplements or doses. For melatonin or any sleep medicine, ask your doctor or pharmacist.
• Our content is not reviewed by a doctor. See our editorial policy.

When to talk to a doctor

CDC advises talking to your healthcare provider if you regularly have problems sleeping or notice signs or symptoms of common sleep disorders, such as insomnia, restless legs syndrome, narcolepsy or sleep apnea [2]. The NHS suggests seeing a GP if changing your sleeping habits hasn’t helped, you’ve had trouble sleeping for months, or it is affecting your daily life in a way that makes it hard to cope [3]. Ongoing loud snoring and daytime sleepiness are also reasons to see a doctor.

If you are pregnant, breastfeeding, taking medication or have a medical condition, ask your healthcare provider before changing your caffeine intake or sleep routine [4].

In an emergency, call your local emergency number.

Accuracy of information

We check our figures against the sources we cite and show the date we last checked them, but guidance changes and mistakes can happen. Always rely on your own healthcare provider for advice about your health.