To track sleep on Apple Watch, set up a sleep schedule in the Sleep app on the watch (or the Health app on iPhone), turn on “Track Sleep with Apple Watch,” then wear the watch to bed with at least about 30% battery. Once that is set up, the watch records your time asleep and — on newer models — your sleep stages automatically each night. Here is the full setup.

What you need first

Sleep tracking works on Apple Watch Series 3 and later running watchOS 7 or newer. To see detailed sleep stages (REM, core, and deep sleep), you need watchOS 9 or later on a supported model. Make sure your watch and iPhone software are up to date in Settings before you start, since Apple has changed the sleep features across watchOS versions. You will also want the watch paired to your iPhone, because the schedule and most of the detailed review happen through the iPhone Health app.

Set up a sleep schedule

You can start on either device:

  1. On iPhone, open the Health app, tap Browse, then Sleep, and tap Get Started (or open the Sleep app directly on the watch).
  2. Set your sleep goal — the number of hours you want — and your bedtime and wake-up schedule.
  3. Choose your Wind Down time, which dims the screen and turns on Sleep Focus to limit distractions before bed.
  4. Turn on Sleep Focus so notifications are silenced while you sleep.

Turn on sleep tracking

Setting a schedule is not the same as recording sleep. To capture your actual sleep data, open the Watch app on iPhone (or Settings on the watch), go to Sleep, and turn on Track Sleep with Apple Watch. With this enabled, the watch uses movement and heart-rate signals to estimate when you fall asleep, how long you sleep, and your sleep stages on supported models.

Wear it — and keep it charged

The watch can only track sleep while it is on your wrist, so you need to wear it to bed. That means charging it at another time of day; many people top up during their evening wind-down or while getting ready in the morning. Apple recommends the watch be charged above roughly 30% before bed so it lasts the night. A snug-but-comfortable band gives the sensors the best contact.

Review your sleep data

In the morning, raise your wrist to see a quick summary, or open the Health app on iPhone and go to Browse > Sleep for the full picture: time asleep, time in bed, sleep stages, and trends over days and weeks. On newer models you can also see overnight metrics like heart rate and, where supported, respiratory rate. Tapping into a night shows a breakdown of time spent in each stage — awake, REM, core, and deep — plotted across the night.

Over time, the trends are more useful than any single night. The Health app will show your average time asleep across a week or month, which makes it easy to spot whether your real sleep matches your intended schedule. If you consistently fall short of your sleep goal, that pattern is the signal worth acting on.

Fixing common problems

If your watch is not recording sleep, run through this quick checklist:

  • Sleep tracking is off. Confirm Track Sleep with Apple Watch is turned on in the Watch app under Sleep — a schedule alone will not record data.
  • The watch died overnight. If the battery dropped below the level needed, it stops tracking. Charge above about 30% before bed.
  • You were outside your sleep schedule. The watch tracks around your set bedtime window, so naps or very off-schedule sleep may not be captured the same way.
  • The band was too loose. The sensors need decent skin contact; snug up the band before sleep.

A note on accuracy

Wrist-based sleep tracking is a helpful estimate, not a medical sleep study. It is good for spotting patterns — consistent bedtimes, how much sleep you tend to get — but it can misjudge exactly when you drifted off, since it infers sleep from movement and heart rate rather than brain activity. Use it to guide habits rather than to diagnose anything.

Where it earns its keep is nudging better routines. Features like Wind Down and a consistent Sleep Focus schedule encourage you to head to bed at the same time each night, and seeing your weekly average can motivate an earlier bedtime. Those behavior changes often help more than the exact minute-by-minute data. For another everyday wrist metric, see our guide to how many steps are in a mile, and if you are building healthier routines, how many steps a day is actually healthy is a good companion read.

This article is for general information and is not medical advice. If you have ongoing sleep problems, talk to a doctor rather than relying on a wearable.