How much sleep debt do I have?
Pick your age group, type how long you usually sleep and over how many nights. The sleep debt calculator adds up the hours you are short of your sleep need and shows how many nights of extra sleep would pay them back.
- Sleep debt (hours)
- 7
Over 7 nights your sleep debt is 7 hours.
- Short each night (hours)
- 1
- Sleep need used (hours)
- 7
- CDC recommends
- 7 or more hours (adults 18 to 60)
- Nights to catch up
- 7
Sleep debt (hours): 7. Over 7 nights your sleep debt is 7 hours.
This calculator gives general information only. It is not medical advice and does not replace a doctor or other health care provider. Talk with a professional about your results. Terms of use
How to calculate
Adds up your sleep debt: the hours of sleep you needed minus the hours you slept, over a number of nights, with the CDC’s recommended hours for your age and the nights it takes to catch up.
Example with the default inputs (Age group 18 to 60, Sleep you got (hours a night, average) 6, Nights 7, Extra sleep to catch up (hours a night) 1): Over 7 nights your sleep debt is 7 hours.
Method: Sleep debt = (need − slept) × nights, or 0; nights to catch up = sleep debt ÷ extra sleep a night, rounded up.
- The need is the CDC’s recommended minimum for the age group unless you type your own.
- Sleeping more than your need on some nights cancels shortfalls on others (the average is used).
- Catching up assumes the same extra sleep every night; hours repaid do not measure how rested you feel.
Worked examples
Each example is checked against the calculator on every build.
- Age group 18 to 60, Sleep you got (hours a night, average) 6, Nights 7, Extra sleep to catch up (hours a night) 1 gives Sleep debt (hours) 7, Short each night (hours) 1, Sleep need used (hours) 7, Nights to catch up 7, CDC recommends 7 or more hours (adults 18 to 60).Source: CDC, About Sleep: recommended hours a day, teens 13 to 17 years 8 to 10, adults 18 to 60 years 7 or more, 61 to 64 years 7 to 9, 65 and older 7 to 8, https://www.cdc.gov/sleep/about/index.html (retrieved 2026-10-05)
- Age group 13 to 17, Sleep you got (hours a night, average) 6.5, Nights 5, Extra sleep to catch up (hours a night) 1.5 gives Sleep debt (hours) 7.5, Short each night (hours) 1.5, Sleep need used (hours) 8, Nights to catch up 5.Source: CDC, About Sleep: recommended hours a day, teens 13 to 17 years 8 to 10, adults 18 to 60 years 7 or more, 61 to 64 years 7 to 9, 65 and older 7 to 8, https://www.cdc.gov/sleep/about/index.html (retrieved 2026-10-05)
- Age group 18 to 60, Sleep you need (hours a night) 8.25, Sleep you got (hours a night, average) 7.4, Nights 14, Extra sleep to catch up (hours a night) 0.75 gives Sleep debt (hours) 11.9, Short each night (hours) 0.85, Sleep need used (hours) 8.25, Nights to catch up 16.
- Age group 65+, Sleep you got (hours a night, average) 7.5, Nights 7, Extra sleep to catch up (hours a night) 1 gives Sleep debt (hours) 0, Short each night (hours) -0.5, Nights to catch up 0.Source: CDC, About Sleep: recommended hours a day, teens 13 to 17 years 8 to 10, adults 18 to 60 years 7 or more, 61 to 64 years 7 to 9, 65 and older 7 to 8, https://www.cdc.gov/sleep/about/index.html (retrieved 2026-10-05)
How it works
- Sleep need used. The hours you type, or, if you leave it empty, the CDC’s recommended minimum for your age group: 8 hours for 13 to 17, 7 hours for 18 to 60, 61 to 64, and 65 and older.
- Short each night = need − hours slept (average a night). A negative value means you slept more than your need.
- Sleep debt = short each night × nights, when the shortfall is above 0; otherwise 0.
- Nights to catch up = sleep debt ÷ extra sleep a night, rounded up to a whole night (0 when there is no debt).
- CDC recommends shows the CDC range for the age group: 8 to 10 hours (13 to 17); 7 or more (18 to 60); 7 to 9 (61 to 64); 7 to 8 (65 and older).
Rules. Need from 4 to 14 hours; sleep from 0 to 24 hours; 1 to 90 nights; extra sleep from 0.25 to 4 hours a night.
Exact arithmetic and output format. The typed values are exact decimals; the results are exact and rounded once, half up. Hours show up to 2 decimals; trailing zeros are dropped.
Assumptions
- The average hours slept stand for every night (long nights offset short ones).
- The same extra sleep every night when catching up.
Worked examples by hand
Adult, 6 hours a night, 7 nights, 1 extra hour. Need 7. Short each night 7 − 6 = 1. Debt 1 × 7 = 7 hours. Catch up 7 ÷ 1 = 7 nights.
Teen, 6.5 hours, 5 nights, 1.5 extra hours. Need 8. Short 8 − 6.5 = 1.5. Debt 1.5 × 5 = 7.5 hours. Catch up 7.5 ÷ 1.5 = 5 nights.
Typed need 8.25, 7.4 hours slept, 14 nights, 0.75 extra. Short 8.25 − 7.4 = 0.85. Debt 0.85 × 14 = 11.9 hours. 11.9 ÷ 0.75 = 15.87, rounded up to 16 nights.
65 and older, 7.5 hours, 7 nights. Need 7. Short 7 − 7.5 = −0.5, so the debt is 0 and no catch-up nights are needed.
Other questions people ask
What is sleep debt?
Sleep debt is the difference between the sleep your body needs and the sleep you get, added up over several nights. An adult who needs 7 hours and sleeps 6 builds 1 hour of debt each night, or 7 hours in a week.
How do I calculate my sleep debt?
Subtract the hours you slept from the hours you need, then multiply by the number of nights. A teen who needs 8 hours and sleeps 6.5 for 5 nights has (8 − 6.5) × 5 = 7.5 hours of sleep debt.
How much sleep do I need?
The CDC recommends 8 to 10 hours for teens 13 to 17, 7 or more hours for adults 18 to 60, 7 to 9 hours for adults 61 to 64, and 7 to 8 hours for adults 65 and older. Some people need more; type your own need if you know it.
Can you catch up on sleep debt?
Sleeping a little longer for a few nights pays back hours of a short-term debt, and this page shows how many nights that takes. Hours repaid do not measure how rested you feel; the lasting fix is regular sleep of the hours you need.
Does sleeping extra one night cancel a short night?
On this page, yes: it uses your average sleep, so a long night offsets a short one. Your body may not count it so neatly, which is why a regular schedule matters.
What are the signs of too little sleep?
Feeling sleepy in the day, trouble concentrating, and dozing off while reading or driving are common signs. If you sleep enough hours but still feel tired, talk with a doctor, because a sleep disorder may be the cause.