# Time awake during the night (WASO) Minutes awake between falling asleep and getting up. Devices under-report it by 12 to 48 minutes; the Night Log shows what they missed. Type: biomarker · Unit: min · Domain: Stress, Rest & Recovery · Accuracy: Estimate · Importance: Supporting Also called: wake after sleep onset, awake time, night wakings, restless time, time awake in bed ## In one sentence The minutes you were awake between first falling asleep and getting up, which VT works out for itself from your sleep window and your total sleep. ## Why it matters Wake inside the night is what makes a night feel broken, and it is the component of sleep that rises most with age in laboratory records: 48 minutes on average across healthy adults, rising by 9.7 minutes per decade (Boulos 2019). It is also the number consumer devices get most wrong, which is why VT calculates it rather than taking the device's word, and why the Night Log exists. ## What moves it Upward: alcohol (a consolidated first half of the night and a broken second half, at every dose; Ebrahim 2013), a late meal, caffeine, a full bladder, pain, heat, noise, worry, a partner, a pet, and age across populations. Downward: regular timing, a dark cool quiet room, and not lying in bed awake, since time in bed after you are done sleeping counts. ## How to measure it well Use the Night Log: a tap for a toilet trip or for lying awake, with an end time you can estimate. In the morning VT draws your entries over the device's chart, so you can see which wakings it caught and which it slept through, because the device sees lying still as sleep. At launch the entries do not change the number. ## How Vitality Tracker uses it Worked out, in your own time zone, as the sleep window minus total sleep. It is one third of the continuity component of the Sleep Health Index, on the same three tiers as efficiency; a component of the nightly sleep score, judged against your own usual so that a device that always reports a lot of awake time is not penalized; and a secondary reading in Symptom Radar (weight 0.7, higher is the direction it watches). ## How far to trust the number Estimate. Consumer wearables underestimate wake after sleep onset by 12 to 48 minutes; one device in the sleep specification's sources reported four minutes of wake against a laboratory figure of 42. In the one ring study that reported it, the device's wake figure was not different from the laboratory's on average but drifted further from it the more wake there was (de Zambotti 2019). Read the series on one device, and read it with the Night Log. ## Method WASO = (wake time − sleep onset) − total sleep. Continuity scoring, the WASO anchor points and the device-bias table are in the sleep specification, §5.4, §6.3 and §7.4. ## Sources 1. Boulos MI, et al. Normal polysomnography parameters in healthy adults. Lancet Respir Med 2019;7:533–43. [doi:10.1016/S2213-2600(19)30057-8]() 2. Ebrahim IO, et al. Alcohol and sleep I: effects on normal sleep. Alcohol Clin Exp Res 2013;37:539–49. [doi:10.1111/acer.12006](https://doi.org/10.1111/acer.12006) 3. de Zambotti M, Rosas L, Colrain IM, Baker FC. The Sleep of the Ring: comparison of the ŌURA sleep tracker against polysomnography. Behav Sleep Med 2019;17:124–36. [doi:10.1080/15402002.2017.1300587](https://doi.org/10.1080/15402002.2017.1300587) 4. Vitality Tracker Sleep Scoring Methodology, open specification v2.0.1, public edition. [doi:10.5281/zenodo.23223863](https://doi.org/10.5281/zenodo.23223863). ## Related - [Sleep efficiency](https://vitalitytracker.app/knowledge/sleep-efficiency) - [Time to fall asleep](https://vitalitytracker.app/knowledge/time-to-fall-asleep) - [Night Log](https://vitalitytracker.app/knowledge/night-log) - [Total sleep](https://vitalitytracker.app/knowledge/total-sleep) - [Symptom Radar and Symptom Trend](https://vitalitytracker.app/knowledge/symptom-radar-and-symptom-trend) Reviewed October 2026 · v1 Source: https://vitalitytracker.app/knowledge/time-awake-during-the-night