Health Tool

Sleep Calculator

Calculate your optimal sleep schedule based on 90-minute sleep cycles. Find the best times to go to bed and wake up feeling refreshed.

Using the Sleep Calculator

Waking up feeling groggy is often a result of being interrupted during a deep sleep phase. This calculator uses 90-minute sleep cycles to find the ideal moments for you to wake up or drift off, ensuring you feel refreshed.

How it Works

Select your target "Wake Up Time" to find out when you should go to bed.

Alternatively, use the "If I go to bed now" feature to find the best wake-up windows.

Review the 4-6 suggested times that correspond to full 90-minute cycles.

Aim for 5 or 6 cycles (7.5 to 9 hours) for peak mental performance.

What time do you want to wake up?

Time to fall asleep

Sleep Tip: The average sleep cycle is 90 minutes. Waking up at the end of a cycle helps you feel more refreshed and reduces grogginess.

About Sleep Cycles

Stage 1: Light Sleep

Transition from wakefulness, 5-10 minutes.

Stage 2: Deeper Sleep

Body temperature drops, heart rate slows, 20-25 minutes.

Stage 3: Deep Sleep

Restorative sleep for physical recovery, 20-40 minutes.

REM Sleep

Dreaming and memory consolidation, 10-60 minutes.

Recommended Sleep Duration

Adults (18-64): 7-9 hours
Teenagers (14-17): 8-10 hours
Older adults (65+): 7-8 hours