Sleep Debt Calculator
Enter how long you slept each night and see how far behind you are, which nights did it, and how long it takes to catch up without wrecking your wake time.
The CDC recommends 7 or more hours for adults and 8 to 10 for teens. Not sure what you need? 8 hours is a fair place to start.
- Night 11h short
- Night 21h short
- Night 31h short
- Night 41h short
- Night 51h short
- Night 61h short
- Night 71h short
About a full night of sleep.
- Average night
- 7h
- Nights short
- 7 of 7
- Shortest night
- 1h short
- Every night
Night 1: 7 hours, 1 hour short. Night 2: 7 hours, 1 hour short. Night 3: 7 hours, 1 hour short. Night 4: 7 hours, 1 hour short. Night 5: 7 hours, 1 hour short. Night 6: 7 hours, 1 hour short. Night 7: 7 hours, 1 hour short.
Paying it back
Going to bed 45 minutes earlier and getting up at the usual time, you would make up 7 hours in about 10 nights.
Earlier nights work better than a long lie-in, which pushes your body clock later and makes Sunday night harder. Find a bedtime that fits your alarm.
Short nights usually start as long evenings.
When the day's work runs late, sleep is what gives. PomoTodo plans the day in focus sessions with a clear finish, so more of the list gets done in working hours and less of it follows you to bed.
Free plan tracks unlimited focus time across unlimited tasks. No card required.
It is Thursday, you have hit snooze twice, and you cannot tell whether you are tired or just busy. Monday was about six hours, Tuesday was less, and Wednesday is a blur.
Sleep debt puts a number on that feeling. It is the gap between the sleep you need and the sleep you got, added up night by night. Enter the last week or two, as hours slept or as bed and wake times, and the calculator totals the gap, shows which nights caused it, and works out how many slightly earlier nights it takes to close.
The nights you enter are saved in this browser only, so you can come back tomorrow and add last night.
What is sleep debt?
Sleep debt, sometimes called a sleep deficit, is the running total of sleep you needed and did not get. If you need 8 hours and sleep 6 for five nights in a row, you are 10 hours down by Friday.
It matters more than it feels like it does. In a 2003 study published in the journal Sleep, healthy adults kept to 6 hours or less in bed a night for two weeks built up performance deficits equal to up to two nights of no sleep at all. Their own ratings of sleepiness barely rose after the first few days, so they did not notice how far they had slipped.
Can you catch up on sleep at the weekend?
Partly, and less than it feels like. In a 2019 University of Colorado Boulder study, people who slept too little during the week and then slept as long as they liked at the weekend made up only about an hour of sleep over those days. Their body clocks also shifted later, which makes the next Sunday night harder.
A steadier way to pay it back is to go to bed a little earlier for a run of nights and keep your wake time the same. That is the catch-up plan the calculator gives you, and it lines up with the CDC's first tip for better sleep: the same bedtime and wake time every day.
How much sleep do you need?
Start from the range for your age. The CDC recommends 7 or more hours for adults 18 to 60, 7 to 9 for 61 to 64, 7 to 8 for 65 and older, and 8 to 10 for teens. Where you sit inside that range is personal. The sleep calculator has the full table by age, from newborns up.
When to talk to a doctor
If you are short on sleep because you cannot fall asleep or stay asleep, rather than because the day keeps running late, or if you get plenty of hours and still feel exhausted, a calculator is not the fix. The CDC advises talking to a healthcare provider if you regularly have problems sleeping or notice signs of a sleep disorder.
More tools
Bedtimes and alarm times that line up with full sleep cycles.
A day by day plan for sleep and light around your flight.
A month on one grid, with streaks. Print it if you prefer paper.
Start a timer, tag a project, get hours and what they are worth.
Questions
How do I calculate my sleep debt?
Take the sleep you got each night away from the sleep you need, and add up the differences. If you need 8 hours and slept 6, 7, 6.5, 8 and 5.5 over five nights, you slept 33 hours against a need of 40, so your sleep debt is 7 hours.
How much sleep debt is too much?
There is no official cut off, but small amounts add up faster than they seem. An hour short a night is 7 hours by the end of the week, close to a full night. In one well known study, two weeks of 6 hours or less in bed a night impaired performance as much as up to two nights with no sleep at all.
Can you make up for lost sleep on the weekend?
Only partly. In a 2019 University of Colorado Boulder study, people who slept in at the weekend after a short week made up only about an hour of sleep, and their body clocks drifted later. Going to bed a little earlier for several nights, while keeping the same wake time, is a steadier way to catch up.
How long does it take to recover from sleep debt?
It depends on how much you owe and how much extra sleep you can fit in each night. At 45 extra minutes a night, 6 hours of debt takes about 8 nights to repay. The catch-up plan in the calculator works out your own number.
How much sleep do adults need?
The CDC recommends 7 or more hours a night for adults 18 to 60, 7 to 9 hours for 61 to 64, and 7 to 8 hours for adults 65 and older. Teens 13 to 17 are recommended 8 to 10 hours.
This calculator gives general information built on published research. It is not medical advice.