Sleep Debt Calculator

Short nights add up. Enter what you actually slept over the last seven nights and see the deficit you're carrying — plus a repayment plan that won't wreck your body clock.

6.5hours of sleep debt

Your shortest night was Thu. Adding one extra hour per night clears this in about 7 nights. Go to bed earlier rather than sleeping in — a late wake-up shifts your body clock and makes the next week harder.

Repaying it without wrecking your rhythm

  • Move bedtime 30–60 minutes earlier; keep your wake time fixed within about 30 minutes, weekends included.
  • Cap daytime naps at 20 minutes before 3pm so you don't borrow from tonight.
  • Use the sleep cycle calculator to pick the earlier bedtime that lands cleanly between cycles.
  • If you're in bed long enough but still short, the bed is often the culprit — see our tested mattress rankings.

FAQs

Guide

Understanding your sleep debt result

What sleep debt means

Sleep debt is the gap between the sleep you need and the sleep you actually get, added up over several days. Most adults are advised to aim for at least seven hours a night, but individual needs differ.

Paying it back sensibly

  • Add 30–60 minutes a night over a week rather than one very long weekend lie-in.
  • Protect a consistent wake time; move bedtime earlier instead.
  • Short early-afternoon naps can help, but long or late naps can make night sleep harder.
  • Look at what is cutting sleep short: late screens, caffeine, a hot bedroom or an uncomfortable bed.

When the number stays high

If you regularly spend enough time in bed but still feel unrefreshed, snore loudly, or struggle to fall or stay asleep, a doctor can help rule out sleep disorders. Calculators give general estimates from the numbers you enter. They are planning aids, not medical advice, and they cannot account for health conditions, medications or individual differences.

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