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Sleep Tool

Sleep Debt Calculator

Log how much you slept over the last seven nights and instantly see your cumulative debt, daily deficits, and recovery status.

Last 7 nights
Slide each day to match how long you actually slept.
Sleep debt summary
Based on your goal of 8h per night.

Moderate debt

6h debt

Average sleep: 7h 9m · Total slept: 50h / 56h needed

Today7h (−1h)
Yesterday6h 30m (−1h 30m)
2 days ago8h ✓
3 days ago7h 30m (−0h 30m)
4 days ago6h (−2h)
5 days ago7h (−1h)
6 days ago8h ✓

What is sleep debt?

Sleep debt is the gap between how much sleep your body needs and how much you actually get. It accumulates night after night — not just after one bad evening.

This calculator looks at your last 7 nights and compares them to a personal sleep goal (default 8 hours).

How to interpret your result

| Debt level | What it may mean | | --- | --- | | 0–3 hours | Generally manageable with consistent timing | | 3–7 hours | Noticeable fatigue, mood, or focus effects possible | | 7+ hours | Higher recovery need — prioritize earlier bedtimes |

Sleep debt is not perfectly linear, but tracking weekly patterns helps you spot when your schedule is drifting.

Recovery tips

  • Add 30–60 minutes of sleep for a few nights rather than trying to "pay back" everything in one morning.
  • Keep wake time consistent even on weekends.
  • Pair sleep recovery with light morning exposure and reduced late caffeine.