FREE SLEEP TOOLS / 02
Sleep duration calculator
How much time did you actually sleep?
Separate time in bed from estimated time asleep.
How the calculation works
Enter the time you went to bed and the time you got up. Add an estimate of the minutes spent falling asleep and awake during the night.
How we calculated it
Compare your estimate with a sleep record
This result depends on the times you entered. NiceSleep can record a session and help you review timing and patterns alongside your own observations.
iOS 1.5.15: choose 3 saved recordings per sleep session for full playback; Premium unlocks all. Android: check your installed version; this allowance’s public release is unverified.
Your entries stay on this page. This website does not upload or save them.
Clock times only: no adjustment for daylight-saving changes or travel between time zones.
How we calculated it
How the calculation works
Enter the time you went to bed and the time you got up. Add an estimate of the minutes spent falling asleep and awake during the night.
An end time earlier than the start is treated as the next day. For a later end time that is also on the next day, use the next-day checkbox. Sessions longer than 24 hours are outside this tool’s scope.
Estimated time asleep equals time in bed minus time to fall asleep and time awake. These are estimates from your entries, not measurements. The tool cannot determine sleep quality or sleep stages.
A worked example
From 23:00 to 07:00 is 8 hours in bed. Subtract 20 minutes to fall asleep and 30 minutes awake: estimated sleep is 7 hours 10 minutes.
Common questions
Does it handle sleep across midnight?
Yes. If the end time is earlier than the start, it is automatically treated as the following day. The result clearly notes the day.
Why is time asleep shorter than time in bed?
Falling asleep and waking during the night are part of time in bed but not time asleep. Subtracting them gives a more useful estimate.
Can this calculate a sleep score?
No. Duration alone does not establish sleep quality. NiceSleep provides estimated session insights; those are also intended for personal wellness rather than diagnosis.