Apple Watch Series 12 and Garmin Cirqa show similar sleep trends over one week

TechRadar’s Matt Evans compared sleep scores from an Apple Watch Series 12 and a Garmin Cirqa worn overnight for one week. Evans says Apple’s Vitals app needed seven nights to establish his baseline before providing its Readiness Score.

The scores differed on individual nights. On the first night, Apple recorded 93 and Garmin 62. On the sixth, Apple recorded 68 while Garmin reached 87. Evans says he had no explanation for the sixth-night gap.

Despite those differences, the devices showed broadly similar weeklong trends, with scores rising, dipping in the middle and finishing high. At the end of the week, Apple gave Evans a Readiness Score of 7/10; Garmin Connect showed 70/100. Evans said both indicated a similar level of readiness.

The article also cites research by Terra, a health data API company, which examined 77,000 nights of sleep data across six wearable companies. It found that trackers generally converged on sleep duration and broad trends, but differences could appear in individual readings. The study said agreement on light, deep and REM sleep stages could diverge by hours in direct comparisons.

Evans concludes that both watches appeared internally consistent in his comparison, while noting that wearables estimate and can produce differing readings. His results describe his own week of use.