Deep Sleep on Apple Watch and iPhone

Time in the slow-wave stage where the body does most of its physical recovery.

Unithours
Where to find itHealth app > Browse > Sleep > Sleep Stages

What it is

Deep sleep is the most restorative stage physically. It is front-loaded in the night, so a late bedtime cuts into it less than into REM.

How Apple measures it

Apple Watch estimates deep sleep from movement and heart rate and reports minutes per night.

What's a normal range?

Roughly 10 to 25% of total sleep in healthy adults, and it drops with age.

What moves it

Age
Alcohol
Evening hard training
Warm bedroom
Sleep schedule

See Deep Sleep next to your other vitals

Apple Health keeps this number several taps deep. OnlyVitals puts the metrics you pick, including Deep Sleep, on a single dashboard so you can read them at a glance. Everything stays on your device.

One screen for the health numbers you care about.

Get OnlyVitals on the App Store

Frequently asked questions

How much deep sleep do I need?

Healthy adults typically get about 10 to 25% of total sleep as deep sleep, less as they age.

How can I get more deep sleep?

A cool dark room, steady schedule, less evening alcohol and regular daytime exercise are the best-supported levers.

Related metrics

This page is general information, not medical advice. Ranges vary by age, sex, fitness and device. Talk to a clinician about anything that worries you.