Sleep Debt Calculator

Sleep debt is the gap between the sleep you need and the sleep you actually get, added up over several nights. If you aim for 8 hours and sleep 6, you build 2 hours of debt that night.

The CDC advises adults aged 18 to 60 to get 7 or more hours a night, 7 to 9 hours for ages 61 to 64, and 7 to 8 hours from 65. Teenagers are advised 8 to 10 hours. Pick a target that fits your age, then see how far your actual sleep falls from it.

In a controlled laboratory study, volunteers limited to 5 hours of sleep on weeknights who slept freely at the weekend still showed weight gain and reduced insulin sensitivity when short sleep resumed, and the authors concluded that weekend recovery sleep is not an effective strategy to prevent the metabolic dysregulation linked to recurrent insufficient sleep (Depner et al., 2019). Getting enough sleep on most nights is a more reliable approach than relying on catch-up.

There is no exact rule. The calculator shows simple arithmetic: debt hours divided by the extra hours you add each night. For example, 6 hours of debt at 1 extra hour a night is 6 nights. How quickly you feel better varies from person to person.

No. It is a tally of hours against a target you choose, not a medical assessment. If you feel unrefreshed or sleepy in the daytime even when you spend enough time in bed, or you have trouble sleeping most nights, speak to a clinician.

A week is long enough to show a pattern and short enough to remember each night. Longer totals depend on weighting choices that research has not settled, so the calculator does not guess.