Compare calculators

Both calculators run independently — change the inputs on either side to compare results.

REM Sleep Cycle Calculator

Find the ideal bedtime to wake up refreshed by aligning your alarm with the end of a complete 90-minute sleep cycle. Use it any night you want to avoid that groggy, mid-cycle wake-up feeling.

Number of Sleep Cycles

Time to Fall Asleep (minutes)

Personal Cycle Length (minutes)

Fill in the required fields to see your result.

Sleep

Shift Work Sleep Calculator

Calculate when you should go to sleep to get 8 hours of rest before your shift, accounting for commute time. Essential for night-shift and rotating-schedule workers.

Shift Start Time (hours (24h format))

Commute Time (hours)

Fill in the required fields to see your result.

Key differences

	REM Sleep Cycle Calculator	Shift Work Sleep Calculator
Category	Sleep	Sleep
Inputs required	3	2
Result	Total Sleep Duration (minutes)	Recommended Sleep Start (hours)
What it does	Find the ideal bedtime to wake up refreshed by aligning your alarm with the end of a complete 90-minute sleep cycle. Use it any night you want to avoid that groggy, mid-cycle wake-up feeling.	Calculate when you should go to sleep to get 8 hours of rest before your shift, accounting for commute time. Essential for night-shift and rotating-schedule workers.