Sleep Debt Calculator

Add up your sleep shortfall over a week compared with the hours you need and get a plan to pay it back. Example: needing 8 hours but sleeping 6 hours on five nights and 8 hours on two nights builds a debt of 10 hours.

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Hours of sleep you need per night

Hours slept, night 1

Hours slept, night 2

Hours slept, night 3

Hours slept, night 4

Hours slept, night 5

Hours slept, night 6

Hours slept, night 7

How to use the Sleep Debt Calculator

Enter the values in the fields.
Press Calculate to see the result with the steps shown.

Formula and method

Sleep debt = sum of max(0, hours needed – hours slept) over the week. Net = hours needed x 7 – total slept.

Recommended sleep by age

Age	Hours per 24 h
Newborns 0 to 3 months	14 to 17
Infants 4 to 11 months	12 to 15
Toddlers 1 to 2 years	11 to 14
Children 3 to 5	10 to 13
Children 6 to 12	9 to 12
Teens 13 to 18	8 to 10
Adults 18 to 64	7 to 9
Adults 65+	7 to 8

How sleep debt builds

Nightly shortfall	After 1 week
1 hour	7 hours
2 hours	14 hours
3 hours	21 hours

Paying it back

Add 30 to 60 minutes of sleep per night, keep wake time within an hour of normal, nap for 20 to 30 minutes before mid-afternoon and avoid caffeine late in the day.

Cautions

This calculator gives estimates for education and planning, not medical advice. Check with your doctor before major changes to diet, exercise or medicines, especially if you have a medical condition.

Frequently asked questions

What is sleep debt?

The accumulated shortfall between sleep you need and sleep you get.

Can I catch up on weekends?

Partly; steady sleep works better.

How long to recover from sleep debt?

Several days to weeks, depending on size.

How many hours do adults need?

7 to 9.

Can I fully repay it?

Short-term debt yes; long-term effects may linger.

What if I am always tired?

Talk to a doctor about sleep disorders.

Sources

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Effortless Math Team

12 minutes ago