About the Sleep Duration Calculator
How long you slept between bedtime and wake time, in hours and minutes, with sleep cycles completed.
Also known as: how much did i sleep, sleep hours calculator, sleep time.
How to use this calculator
- Enter bedtime, wake time, time to fall asleep.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
Sleep = wake time − bedtime − time to fall asleep
Worked example
Using the values pre-filled in the calculator above:
- Bedtime: 23:15
- Wake time: 06:45
- Time to fall asleep = 15 min
the calculator returns:
- Sleep duration: 7 h 15 min
- Hours: 7.25
- Sleep cycles (90 min): 4.8
- Recommended for adults: 7–9 hours