How much deep sleep do you need?

Updated October 31, 2026

Adults typically spend about 10% to 20% of the night in deep sleep, or roughly 40 to 110 minutes across 7 to 9 hours of sleep. There’s no consensus on one ideal number. Feeling refreshed and alert in the morning is a practical sign you’re getting enough.

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Estimate your range

Take 10% and 20% of your total sleep:

6 hours of sleep: 36 to 72 minutes
7 hours of sleep: 42 to 84 minutes
8 hours of sleep: 48 to 96 minutes
9 hours of sleep: 54 to 108 minutes

Why your number changes

Children and adolescents need the most deep sleep, and it declines with age. Your body also regulates it partly on its own: after sleep deprivation, you may spend more time in deep sleep. Deep sleep is most common early in the night.

How to get more deep sleep

Keep a consistent bedtime and wake time
Make your bedroom quiet, cool, and dark
Follow a relaxing bedtime routine
Cut caffeine in the afternoon and evening
Avoid screens for 30 minutes or more before bed

Can an app measure your deep sleep?

Only as an estimate. You can’t know your exact time in each stage without a sleep lab. A 2023 study comparing 11 consumer trackers with a clinical sleep study found that agreement on sleep stages varied widely between devices.

So use SleepBoo’s stages to watch trends over weeks, and pair them with how you feel. Don’t worry about a single night.

Frequently asked questions

Is 30 minutes of deep sleep bad?

One night says little, and an app’s reading is only an estimate. If you often wake up unrefreshed or feel sleepy during the day, talk to a doctor.

How much REM sleep do I need?

REM periods get longer toward morning, so cutting your sleep short can reduce them. There’s more on this in our sleep tracker guide.

Sources

SleepBoo is a wellness app and does not replace medical advice.