Apple Health metrics › Sleep Duration

Sleep Duration on Apple Watch and iPhone

How long you slept last night, from Apple Watch or iPhone Sleep.

What it is

Sleep duration is the base of every recovery metric. Adults generally need seven or more hours a night, according to major sleep-medicine guidance.

How Apple measures it

Apple Watch detects sleep from movement and heart rate. Apple Health logs time asleep, time in bed and, on newer devices, sleep stages.

What's a normal range?

Seven to nine hours is the common adult target. Consistent bed and wake times help as much as the total.

What moves it

• Bed and wake time consistency
• Caffeine and alcohol
• Evening light and screens
• Room temperature
• Training load

See Sleep Duration next to your other vitals

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

Frequently asked questions

How much sleep do adults need?

Seven or more hours per night is the usual recommendation for adults. Needs vary a bit between people.

Is Apple Watch sleep tracking accurate?

It is good at total sleep time and reasonable on stages, but it is not a clinical sleep study. Use trends rather than a single night.

Related metrics

• REM Sleep
• Deep Sleep
• Core Sleep
• Awake Time During Sleep
• Wrist Temperature
• Walking Heart Rate Average

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.