😴 Sleep Cycle Calculator
Find the best time to fall asleep so you wake up between sleep cycles — and feel more refreshed.
Calculator
We include ~15 minutes to fall asleep.
Recommended bedtimes
Based on 90-minute sleep cycles.
General guidance only — not medical advice.
FAQ
How long is one sleep cycle?
On average, a sleep cycle is around 90 minutes, though it varies by person and night.
How many sleep cycles do I need?
Many people feel best with 4–6 cycles (about 6–9 hours). Try a few options and see what works for you.
Why do I wake up tired even after many hours?
If you wake during deep sleep, you may feel groggy. Timing your wake-up between cycles can help.
What if I work night shifts?
You can still use the calculator — just enter the time you plan to wake up.
Is this medically accurate?
It's a general guideline based on average cycle length and fall-asleep time. For medical concerns, consult a professional.