Here’s one cool addition to yesterday’s information about how the Sleep Score feature works on older Apple Watch models: in fact, it even works with third-party accessories, provided they offer a sleep tracking feature. Here are the details.
Sleep Score is not necessarily tied to the Apple Watch sleep tracking feature
As noted by Rudrank Riyam on X, you don’t even need to own an Apple Watch to see your sleep score in the Health app on iOS 26:
Sleep score is independent of the apple watch. This is sleep data from Garmin! pic.twitter.com/ISxuRnK8MG — Rudrank Riyam (@rudrankriyam) September 10, 2025
What’s more, you also don’t need to have watchOS 26 installed on your Apple Watch, since the feature takes into account sleep data that the Apple Watch (and third-party devices) have been collecting natively, decoupled from the system update.
For this reason, you can also retroactively check your sleep score as far back as the first time your device measured your sleep, which means that as soon as you install iOS 26, you’ll be able to check the daily analysis of your sleep based on your own sleep history.
Naturally, if you’d rather get that information right on your wrist, you’ll need an Apple Watch running watchOS 26. That means Apple Watch Series 6 and later, Apple Watch SE 2 and later, and any Apple Watch Ultra model.
How Sleep Score works
The feature grades your sleep based on factors such as duration, bedtime consistency, whether and how often you wake up, and time spent in each sleep stage (deep, core, and REM).
Once the score is calculated, Apple breaks it down into categories and compares each one to the user’s average data, making it easier to understand which aspects can be improved.
According to Apple, the new feature was developed based on more than 5 million nights of sleep data from the Apple Heart and Movement Study. It was also informed by leading guidance from the American Academy of Sleep Medicine, the National Sleep Foundation, and the World Sleep Society.
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