⚡ 100% Free Interactive Calculator Tool
Interactive Alarm Time Calculator
Select your target bedtime or desired wake-up time below to calculate your exact 90-minute sleep cycle alarms.
How the Alarm Time Calculator Works
Human sleep is composed of 90-minute REM and Non-REM cycles. Setting your alarm at the end of a completed 90-minute cycle prevents sleep inertia (the heavy, tired feeling when woken during deep sleep).
People Also Ask (PAA)
❓ Why should I set my alarm in 90-minute increments?
Waking up at the end of a 90-minute cycle occurs during light sleep, making you feel alert immediately upon waking.