CALCULATOR · FREE免费 · Free
Sleep Duration Calculator
Sleep duration is wake time minus bedtime minus latency. It shows minutes, hours, complete cycles and the gap from eight hours; crossing midnight adds 24 hours automatically.
--Minutes · min
--Hours · h
--Cycles · cycles
--vs 8 hours · min
Estimates only; verify on site before ordering or building.
Example
| Item | Value | Unit |
|---|---|---|
| Bed hour | 23 | h |
| Bed minute | 0 | min |
| Wake hour | 7 | h |
| Wake minute | 0 | min |
| Sleep latency | 15 | min |
| Minutes | 465 | min |
| Hours | 7.75 | h |
| Cycles | 5 | cycles |
| vs 8 hours | -15 | min |
Where people go wrong
- Forgetting to subtract latency.
- Subtracting across midnight and getting a negative.
- Treating eight hours as everyone's target.
FAQ
Is 7.75 hours enough?
Most adults need 7 to 9 hours; judge by daytime function and long-term habits.
Do naps count?
This tool covers nighttime only; add naps separately, and keep them short.