Sleep Calculator

Find the best times to sleep and wake up based on 90-minute sleep cycles

Assumes 14 minutes to fall asleep

Set your alarm for...

5:14 AM
4 cycles · 6 hours of sleep
Minimum
6:44 AM
5 cycles · 7.5 hours of sleep
OK
8:14 AM
6 cycles · 9 hours of sleep
Recommended

What happens in each 90-minute cycle?

Stage 1 (NREM)
1–7 min
Light sleep, easy to wake up
Stage 2 (NREM)
10–25 min
Body temperature drops, memory consolidation
Stage 3 (NREM)
20–40 min
Deep sleep, tissue repair, immune boost
REM Sleep
10–60 min
Dreams, emotional processing, learning

How to use:

  • • Choose whether you want to set a wake-up time or a bedtime
  • • Enter your desired time to get three sleep schedule options
  • • The green "Recommended" option gives you 6 complete cycles (9 hours)
  • • Waking up at the end of a cycle reduces grogginess
  • • The 14-minute fall-asleep buffer is based on average sleep latency

❓Sleep Calculator FAQ

🔗Related Tools

TDEE Calculator

Calculate Total Daily Energy Expenditure and calorie needs for your goals

Try this tool→

Age Calculator

Calculate age between two dates

Try this tool→

Tip Calculator

Calculate tip and split bill among multiple people

Try this tool→

Tip: Explore our complete toolkit to find more tools that can help with your workflow. Each tool is designed to work seamlessly with others for maximum productivity.