Apple Watch includes built-in sleep tracking that works automatically when worn to bed. watchOS 26 introduced sleep score, which visualizes sleep quality. The author finds granular notification controls most useful, enabling alerts only for scores of OK (61-80), Low (41-60), or Very Low (0-40), and disabling notifications for High and Very High.\n\nTo set these notifications on iPhone, open the Watch app, go to Sleep > Sleep Score Notifications, and toggle specific ranges. On Apple Watch, go to Settings > Sleep > Sleep Score Notifications.

The sleep score is calculated from sleep duration (50 points), bedtime consistency (30 points), and interruptions (20 points).\n\nSleep score requires watchOS 26 on Apple Watch Series 6 and later, Apple Watch Ultra and later, or Apple Watch SE 2 and later. Apple Watch Series 11 is priced from $299 on Amazon, down from $399. Refurbished options start at $209.