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Sleep debt calculator

Needing 8 hours but averaging 6.5 adds up to 10.5 hours of sleep debt a week. Going to bed an hour earlier repays it in about 11 nights.

Sleep I need (hours)
Average I got this week

Your sleep debt

  1. 10.5 howed over the last 7 nights
  2. 90 minshort each night on average
  3. 11 nightsto repay at +1 h a night

What to do with the number

  1. Repay it gradually: go to bed 30 to 60 minutes earlier for a week rather than sleeping until noon on Saturday.
  2. Keep your wake time fixed while you repay, so your body clock does not drift.
  3. If the number is large every week, the real fix is a bedtime you can keep, not a recovery weekend.

Common questions

What is sleep debt?

The difference between the sleep you need and the sleep you get, added up over days. A 7-hour need and 6 hours a night is 7 hours of debt in a week.

Can you catch up on sleep at the weekend?

Partly. Extra sleep helps you feel better, but long lie-ins shift your body clock and make Monday morning harder.

How much sleep do I need?

Adults 18 to 60 need at least 7 hours. Use the sleep-by-age calculator for other ages.

One thing this cannot do

It uses one average for the whole week. Two all-nighters and five good nights add up the same as seven slightly short nights, but they do not feel the same.

Sources: CDC, About Sleep.General information, not medical advice.

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