Sleep Duration Calculator — Bedtime to Wake Time
Enter bedtime and wake time to get total sleep hours, with a band rating.
Input Data
Hour you went to bed (0–23).
h
Minute you went to bed.
min
Hour you woke (0–23).
h
Minute you woke.
min
Results
Total sleep hours.
7.5h
Band rating explanation.
睡眠時長 = 7 小時 30 分（7.5 h）。
At a glance:Sleep duration = wake time − bedtime, with any wake after midnight adding 24h. Adults are recommended 7–9h. Complements sleep-cycle.
Formula
duration = (wakeHour×60+wakeMin) − (bedHour×60+bedMin); +24h if negative.
How to Use
- Enter bedtime and wake time.
- The tool gives total hours and a band note.
Case Studies
23:00 → 07:00 → 8h
420 − 1380 = −960 → +1440 = 480 min = 8h.
FAQ
Is it accurate?
It measures time in bed, not actual sleep; brief awakenings are not subtracted.
How is it different from sleep-cycle?
Sleep-cycle suggests wake times; this measures actual duration.
What is it used for?
Tracking sleep habits.
How precise?
One decimal place.
Related Tools
References
Content review: Calculatorism Science Team. Results are for reference only; please refer to the relevant authorities for the official figures.