Sleep Calculator
Calculate the ideal time to wake up or fall asleep to avoid waking up groggy in the middle of a sleep cycle.
Calculation Inputs & Parameters
07:00
15
(Default)
Recommended Bedtime
11:15 PM (5 cycles / 7.5h)
6 Full Cycles (9 hours)
9:45 PM
4 Full Cycles (6 hours)
12:45 AM
Sleep Cycle Length
90 minutes each
How the Calculation Works
Human sleep cycles average 90 minutes. Waking at cycle completion prevents sleep inertia.
Formula: Bedtime = Wake Time - (Cycles × 90 mins) - Latency
Practical Worked Example
Given Inputs: Wake at 7:00 AM
Calculated Output: Sleep at 11:15 PM (5 cycles)
- 7:00 AM - 7h 45m = 11:15 PM.
Pro Tip: To ensure you wake up refreshed, try to align your wake-up time with the end of a 90-minute sleep cycle.