About the Nap Calculator
Best nap lengths (power nap, full cycle) and when to wake, including caffeine-nap timing.
Also known as: power nap calculator, nap length, best nap time.
How to use this calculator
- Enter nap starts at, 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
20 min for alertness · 90 min for a full cycle
Worked example
Using the values pre-filled in the calculator above:
- Nap starts at: 14:00
- Time to fall asleep = 10 min
the calculator returns:
- Power nap (20 min) — wake at: 14:30
- Short nap (30 min): 14:40
- Full cycle (90 min): 15:40
- Avoid: 45–60 min (wakes you in deep sleep)