When you woke up
OPTICALMOTION
Accuracy
93%
Wake Time Agreement
of nights within half an hour, against a consumer smartwatch worn on the same nights (106 nights, 56 subjects)
Reference standard
Consumer smartwatch
Sample size
56 participants
The Ultrahuman Ring places the moment you woke a typical 8.0 minutes from an FDA-cleared home sleep test reading brain activity, and a consumer smartwatch agrees.
8.0 mintypical night-to-night error, against the home sleep test
7.9 minaverage per-night difference, against a consumer smartwatch
93%of nights within half an hour, against the smartwatch
+3.6 minthe ring calls waking late, on average
The end of the night is rarely a single moment. Most people surface, drift back under, and surface again before they are properly up, which leaves a stretch of minutes that is neither clearly asleep nor clearly awake. Placing one timestamp inside that stretch is what the Ultrahuman Ring and its reference are both being asked to do.
Against that home sleep test — a home sleep study rather than a laboratory polysomnogram — the typical night-to-night error is 8.0 minutes, across 20 paired nights from 4 people. Against a consumer smartwatch, on the algorithm shipping today, 93% of nights fall inside half an hour, with an average per-night difference of 7.9 minutes across 106 nights from 56 people.
These are per-night figures rather than an average across nights.
What difference remains runs in one consistent direction: the Ultrahuman Ring places waking about three and a half minutes late against the home sleep test, with a consumer smartwatch showing the same pattern. A steady offset moves every night by the same amount and leaves the shape of your week unchanged.