Find your optimal bedtime or wake-up time based on 90-minute sleep cycles. Wake up feeling refreshed by aligning with your natural sleep rhythm.
Welcome to TooliFyra's Sleep Calculator - a science-based tool that helps you optimize your sleep schedule using the 90-minute sleep cycle formula. The average person goes through 4-6 sleep cycles per night, each lasting approximately 90 minutes. Waking up at the end of a cycle (rather than in the middle) leaves you feeling more refreshed and alert.
Our calculator offers two pathways: find the best time to go to bed based on your desired wake-up time, or find the best time to wake up based on when you go to bed.
Everyone can improve sleep quality by waking up at the right point in their sleep cycle. Shift workers can optimize irregular sleep schedules. Parents can plan bedtime routines. Students and professionals can maximize alertness during the day.
Daily sleep optimization, jet lag recovery, shift work planning, improving morning alertness, sleep schedule reset, and overall sleep health improvement.
Our Sleep Calculator includes a live countdown timer and accounts for fall-asleep time, making it more practical than simple sleep cycle calculators.
A sleep cycle lasts about 90 minutes and includes light sleep, deep sleep, and REM sleep. Completing full cycles leads to more restful sleep.
Most adults need 4-6 complete cycles (6-9 hours). 5 cycles (7.5 hours) is considered optimal for most people.
This is the average time it takes you to fall asleep after getting into bed. The default is 15 minutes, but you can adjust it.
Sleep cycles vary between individuals (80-110 minutes). The 90-minute average is well-established in sleep research and works well for most people.
Yes, completely free with no usage limits.