Sleep Debt Calculator
Adds up how much sleep you missed against what you need.
Share sends a link that reopens these numbers. Copy details pastes the full breakdown as a list.
The formula
debt = (need × nights) − total hours slept
Extra sleep on one night offsets a shortfall on another, and the debt does not go below zero. Leave a night blank to skip it.
What to watch out for
Enter the hours you actually slept, not the time you spent in bed. Your need is personal: adults generally need 7–9 hours, and waking without an alarm and staying alert through the day suggests you are getting enough.
If you are often short of sleep despite having time for it, or still tired after a full night, it is worth raising with a doctor.
Frequently Asked Questions
How much sleep debt is 6 hours a night for a week?
14 hours, if you need 8 hours a night.
Can I catch up at the weekend?
Partly. Recovery sleep eases sleepiness and improves mood, but studies suggest attention and metabolic effects may not fully recover after a couple of long nights. Going to bed a little earlier over several days is the more realistic fix.
What about a mixed week?
With 8 hours needed and nights of 7, 6.5, 6, 7, 6, 8.5, 9 hours, the debt is 6.0 hours, averaging 7.1 hours a night.