Sleep Debt Recovery
Calculator

Inputs

Final sleep debt
82 hours

Note

debt_never_clears

Results

Final sleep debt
82 hours
Weekly net change
4.5 hours
Weeks to clear the debt
Not reached within the projection
Total shortfall
120 hours

Projected path over the weeks

032.565.097.513014.758.512.316.0
  • Net sleep debt
  • Baseline sleep debt

Week-by-week schedule

17.503.0014.5017.50
27.503.0019.0025.00
37.503.0023.5032.50
47.503.0028.0040.00
57.503.0032.5047.50
67.503.0037.0055.00
77.503.0041.5062.50
87.503.0046.0070.00
97.503.0050.5077.50
107.503.0055.0085.00
117.503.0059.5092.50
127.503.0064.00100.00
137.503.0068.50107.50
147.503.0073.00115.00
157.503.0077.50122.50
167.503.0082.00130.00

Comparison

ScenarioFinal sleep debtTotal shortfall
Doing nothing130.00120.00
Your plan82.00120.00

Formula

debt(w) = max(debt(w−1) + 5(need − actual) − weekend recovery, 0)

= 82.00

Note

These are deliberately simplified models. They assume a constant rate and ignore metabolic adaptation, water weight, hormones, illness, medication, sleep and stress, so individual results vary widely — two people following the same plan can land far apart. The 7700 kcal per kilogram of body fat figure is a population average, not a personal constant. A large deficit, a fast mileage or load ramp, or a very low target body fat can be harmful; treat any flagged rate as a reason to slow down. This is NOT medical, dietetic or coaching advice — consult a qualified doctor, registered dietitian or accredited coach before acting on any projection here, and especially if you are pregnant, under 18, or managing any medical condition.

More in Health progress

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Frequently asked questions

What exactly is 'sleep debt' and how is it calculated?+

Sleep debt is the cumulative shortfall between the sleep you actually got and the amount your body needs, tracked over days or weeks — the calculator sums each night's deficit (or surplus) to show your running total.

Can I fully repay sleep debt with one long night of sleep?+

Not completely — a single long sleep session can reduce acute sleepiness and some cognitive effects, but research suggests full recovery from an accumulated deficit, especially a large one, takes multiple nights of adequate or slightly extended sleep.

Why does the calculator suggest gradual extra sleep rather than one big catch-up?+

Spreading recovery sleep across several nights (an extra 30-60 minutes per night, for example) is generally more sustainable and effective than trying to erase a multi-night deficit in a single marathon sleep, which can also disrupt your regular sleep schedule.

Does napping count toward paying off sleep debt?+

Short naps can offset some of the immediate effects of sleep debt, like alertness, but they generally count for less than nighttime sleep toward the calculator's cumulative debt figure, since they don't provide the same proportion of deep and REM sleep.

Is there such a thing as sleep credit if I sleep more than I need?+

The concept is debated, but most models treat above-need sleep as reducing existing debt rather than banking a surplus for future use — you can't typically 'pre-sleep' to offset an anticipated future short night.