How accurate are wrist-based sleep trackers?

Studies show consumer sleep trackers are reasonably accurate for total sleep time and can distinguish wake from sleep. Sleep stage classification is less reliable than clinical polysomnography but useful for trend tracking.

What is a good sleep score?

Most scoring systems use 0-100. Above 80 is generally considered good. More importantly, track your own baseline and notice what habits correlate with your best scores.

Best Sleep Tracker Watches 2026