# How much sleep debt do I have?

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.

- Page: https://www.acalculator.org/health/sleep-debt-calculator
- JSON spec: https://www.acalculator.org/health/sleep-debt-calculator.json
- Version: 3604a5b967c2

## Default answer

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.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| age | Age group | Your age group, which sets the CDC’s recommended hours of sleep. |
| need | Sleep you need (hours a night) | Optional: the hours you need to feel rested; left empty, the CDC minimum for your age group. |
| slept | Sleep you got (hours a night, average) | The average hours you actually slept each night. |
| nights | Nights | How many nights to add up, for example 7 for a week. |
| extra | Extra sleep to catch up (hours a night) | How much more than your need you can sleep each night to pay the debt back. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| debt | Sleep debt (hours) | (Need − slept) × nights; 0 when you slept your need or more. |
| perNight | Short each night (hours) | Need − slept, a night; 0 or less means no shortfall. |
| needUsed | Sleep need used (hours) | The need you typed, or the CDC minimum for your age group. |
| recommended | CDC recommends | The CDC’s recommended sleep for the age group. |
| catchUp | Nights to catch up | Sleep debt ÷ extra sleep a night, rounded up to whole nights. |

## Method

Sleep debt = (need − slept) × nights, or 0; nights to catch up = sleep debt ÷ extra sleep a night, rounded up.

## Assumptions

- 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

1. age = adult, slept = 6, nights = 7, extra = 1 gives debt = 7, perNight = 1, needUsed = 7, catchUp = 7, recommended = 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).
2. age = teen, slept = 6.5, nights = 5, extra = 1.5 gives debt = 7.5, perNight = 1.5, needUsed = 8, catchUp = 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).
3. age = adult, need = 8.25, slept = 7.4, nights = 14, extra = 0.75 gives debt = 11.9, perNight = 0.85, needUsed = 8.25, catchUp = 16.
4. age = senior, slept = 7.5, nights = 7, extra = 1 gives debt = 0, perNight = -0.5, catchUp = 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).

## FAQ

### 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.

## Sources

- Centers for Disease Control and Prevention. About Sleep: How much sleep do I need?, retrieved 2026-10-05. https://www.cdc.gov/sleep/about/index.html
- National Heart, Lung, and Blood Institute. How Sleep Affects Your Health (sleep deficiency), retrieved 2026-10-05. https://www.nhlbi.nih.gov/health/sleep-deprivation/health-effects