How do I make my Apple Watch sleep data more accurate?

Author: Taryn Labadie  |  Last update: Tuesday, October 28, 2025

Get more accurate results with your Apple Watch In the Watch app on your iPhone, tap the My Watch tab, then tap Sleep. Then tap Track Sleep with Apple Watch to turn on this setting. To get the most accurate results when wearing your watch to sleep: Turn on Charging Reminders.

How do I force my Apple Watch to sync sleep data?

In the Watch app, go to Sleep and ensure Track Sleep with Apple Watch is toggled on. Also go to Passcode and ensure Wrist Detection is turned on, as the Watch needs to be able to record a heart rate to determine what stages of sleep you're in.

How accurate is Apple Watch sleep tracking?

By comparison, Apple Watch has a very high sleep sensitivity (97.9 percent in the validation set) and a high specificity of 75.0 percent.

Why does my Apple Watch show so little deep sleep?

Apple Watch was about 62% accurate in detecting deep sleep, confusing it for core sleep 38% of the time. This means your Apple Watch is likely to underestimate deep sleep. The numbers above giving normal values are based on Apple Watch data, so they take into account this likely understimate.

How do I get accurate sleep data?

To get accurate measures, you would need to do a clinical sleep study which monitors sleep status changes and duration using various brainwaves - as opposed to finger movement, pulse O2, temperature, and HR. If you are concerned about something, contact your medical provider.

Apple Watch Sleep Tracking Setup Guide & Tutorial

Why is the Apple Watch not tracking sleep?

If your watch battery dies, it won't track your sleep data. Make sure that you're wearing your Apple Watch at a comfortable fit. If your watch is too loose, the accelerometer might register too much movement during your natural sleep.

How much REM sleep is normal?

With the normal adult averaging a total of 3-5 cycles per night, 20-25% of sleep should account for REM for every 7-8 hours spent in bed. This can be variable depending on age, lifestyle, and other factors, especially as REM intervals decline as we get older.

Why am I only getting 7% deep sleep?

Deep sleep occurs multiple times throughout the sleep period, but factors like insomnia, stress, and aging can affect duration of deep sleep. Get more deep sleep by taking a warm bath, improving your diet, or listening to binaural beats before bed.

Does Apple Watch overestimate sleep?

Oura Ring did not significantly underestimate or overestimate any of the four sleep stages, while Apple Watch overestimated light sleep by an average of 45 minutes and deep sleep by an average of 43 minutes.

How do I make Apple sleep tracking more accurate?

Get more accurate results with your Apple Watch

In the Watch app on your iPhone, tap the My Watch tab, then tap Sleep. Then tap Track Sleep with Apple Watch to turn on this setting. To get the most accurate results when wearing your watch to sleep: Turn on Charging Reminders.

How does my watch know I'm in deep sleep?

Accelerometers measure how much movement you're making while you sleep. This data is then analyzed using an algorithm to estimate sleep time and quality.

How much deep sleep should you get?

You should aim for about 13 to 23 percent of your sleep to be in these stages. So, if you get 8 hours of sleep, you should be getting anywhere between an hour and just under two hours of deep sleep. However, it's important to note that what time you go to bed can greatly influence how much deep sleep you get.

How do I fix my Apple sleep data?

Apple Watch Not Tracking Sleep? Here's How I Fixed Mine
  1. Make Sure Sleep Tracking is Turned On. ...
  2. Set Up a Sleep Schedule. ...
  3. Reset Your Sleep Schedule to Resolve Issues. ...
  4. Make Sure You're Using Sleep Focus. ...
  5. Remove and Prioritize Data Sources. ...
  6. Make Sure You Have Enough Battery to Last the Night.

Does the Apple Watch automatically detect sleep?

Right now, the Apple Watch can only track your sleep if you tell it when you're going to bed and wake up, or if you manually start the Sleep Focus mode.

How do I sync my Apple Watch to my sleep watch?

Open Sleep Watch App on your iPhone. If you see 'Welcome to Sleep Watch', complete all the set-up / on-boarding steps until you see the 'Today' view. Keep the Sleep Watch App on the iPhone open to the 'Today' view. This triggers a sync to your New Apple Watch.

What is the ideal sleep cycle?

An average sleep cycle lasts about 90 minutes. Ideally, you need four to six cycles of sleep every 24 hours to feel fresh and rested. Each cycle contains four individual stages: three that form non-rapid eye movement (NREM) sleep and one rapid eye movement (REM) sleep.

What part of the body does not sleep while sleeping?

A recent study has, however, put to rest this age-old myth citing scientific evidence. Researchers at Vanderbilt University in Nashville, Tennessee, have found that while you are asleep, the only body part that remains active is the ear.

How to interpret Apple Watch sleep data?

A small chart shows how many minutes you were awake, and how much time you spent in each of the three basic sleep stages: REM (where most dreaming happens), deep (a restorative phase for mind and body), and core (Apple's term for light sleep, which is essentially the time not spent in REM or deep sleep).

How to increase REM sleep?

How to Increase REM Sleep
  1. Create a relaxing bedtime routine to help you wind down each night.
  2. Set a sleep schedule and stick to it. ...
  3. Avoid nicotine and caffeine. ...
  4. Exercise and spend some time outside in natural sunlight every day.
  5. Avoid alcohol and meals close to bedtime.

What is pink noise for sleep?

Pink noise emphasizes lower frequencies, making it sound deeper and more soothing. It's more like the natural sounds of a gentle rain, wind rustling through trees, or waves on a beach. Many people find the softer, more balanced sound more pleasant and relaxing than white noise.

How much deep sleep is normal on an Apple Watch?

The average Apple Watch user gets 49 mins of deep sleep per night —about 13% of total sleep time. (If you did the math and calculated the average person gets about 6.5 hours of sleep, that's right—most people aren't getting enough sleep.) 13% is the average, but there's a lot of variance.

Which is better, REM or deep sleep?

The third and fourth stages are deep sleep. Though REM sleep was previously believed to be the most important sleep phase for learning and memory, newer data suggests that non-REM sleep is more important for these tasks, as well as being the more restful and restorative phase of sleep.

Why am I waking up during REM sleep?

Most people awaken after a normal night's sleep in the morning at some point in a REM episode, often in the midst of a dream. This suggests that there is a threshold for awakening and consciousness and that it is REM that drives the sleeping brain to reach that threshold.

Previous article
Do you shave or exfoliate first?
Next article
How to tell if a massage is a cop?