Sleep Cycle Planner Formula

Understand the math behind the sleep cycle planner. Each variable explained with a worked example.

Use the Sleep Cycle Planner

Formulas Used

Wake After 4 Cycles (6h)

wake_4_cycles = sleep_start_total_min + 360

Wake After 5 Cycles (7.5h)

wake_5_cycles = sleep_start_total_min + 450

Wake After 6 Cycles (9h)

wake_6_cycles = sleep_start_total_min + 540

Total Sleep (5 cycles)

total_sleep_5 = 450

Variables

VariableDescriptionDefault
bedtime_hourBedtime (hour, 24h)22
bedtime_minBedtime (minutes)30
fall_asleep_minTime to Fall Asleep(minutes)15
sleep_start_total_minDerived value= bedtime_hour * 60 + bedtime_min + fall_asleep_mincalculated

How It Works

Sleep Cycle Planning

A complete sleep cycle lasts approximately 90 minutes and includes light sleep, deep sleep, and REM sleep.

Ideal Wake Time = Bedtime + Fall Asleep Time + (90 min x Cycles)

Recommended Sleep Cycles

| Cycles | Sleep Duration | Best For | |---|---|---| | 4 | 6 hours | Minimum rest | | 5 | 7.5 hours | Most adults | | 6 | 9 hours | Recovery, teens |

Waking at the end of a cycle (during light sleep) makes you feel more alert than waking mid-cycle.

Worked Example

Bedtime at 10:30 PM, takes 15 minutes to fall asleep.

bedtime_hour = 22bedtime_min = 30fall_asleep_min = 15
  1. 01Sleep starts at 10:45 PM
  2. 024 cycles: 10:45 PM + 6h = 4:45 AM
  3. 035 cycles: 10:45 PM + 7.5h = 6:15 AM
  4. 046 cycles: 10:45 PM + 9h = 7:45 AM

Ready to run the numbers?

Open Sleep Cycle Planner