Sleep Calculator
Six cycles beat seven interrupted ones. Work backward from your alarm.
Recommended bedtime (falls asleep ~15 min)
21:15 PM-ish
| Option | Lights out |
|---|---|
| 6 cycles (9h) | 21:15 |
| 5 cycles (7h 30m) | 22:45 |
| 4 cycles (6h) | 00:15 |
| 3 cycles (4h 30m) | 01:45 |
How the Sleep Calculator works
The calculation follows the standard method used across the US — no shortcuts, no hidden assumptions. Here is exactly what happens behind the scenes:
Frequently Asked Questions
How does the Sleep Calculator work?
Enter your numbers above and results update instantly using standard formulas, computed entirely on your device.
Is the Sleep Calculator free to use?
Yes — completely free with no signup required, and it works on phones, tablets, and desktops.
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