Your sleep log

Enter how much you slept each of the last 7 nights. Use decimals — e.g. 6.5 = 6 hours 30 min.

Your sleep need (hours per night)

hrs

Don't know your ideal sleep need? Use our Sleep Need Calculator ↗ — then come back.

Or pick by age group

Quick fill

Weekdays Weekends

Actual sleep per night

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Your sleep debt picture

Fill in your last 7 nights on the left — you'll see a day-by-day chart, your total debt, and a recovery timeline.

total sleep debt this week

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average nightly deficit

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average sleep per night

No Debt

Mild

1–3h

Moderate

4–7h

High

8–13h

Severe

14h+

Your week at a glance

Met target Deficit Target

Recovery estimate

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How to pay back your sleep debt:

What sleep debt actually does to you

Sleep debt is cumulative and its effects compound. Missing just one hour a night for a week produces the same cognitive impairment as a full night without sleep — but unlike obvious all-nighters, the gradual decline feels normal, so most people don't notice how impaired they've become.

24%Drop in immune function after 6 hrs/night for one week

3×Higher accident risk with fewer than 6 hrs of sleep

40%Reduction in ability to make new memories when sleep-deprived

11 daysTime needed to fully recover from one week of 6-hour nights (Penn study)

The myth that you can "sleep in" on weekends to cancel weekday debt is partly true for short-term deficits — but chronic sleep deprivation causes lasting neurological changes that don't fully reverse in a single long sleep.

NOTE: This calculator estimates sleep debt based on self-reported hours and a general sleep need target. It does not account for sleep quality, sleep disorders (e.g. sleep apnoea), or circadian disruption. If you consistently struggle to fall or stay asleep, speak to a healthcare provider. Persistent fatigue despite adequate sleep time may signal an underlying condition.