Sleep Calculator

Wake up refreshed by timing your alarm to complete 90-minute sleep cycles — or find the ideal bedtime for a target wake time.

💤 Cycle science

Each sleep cycle is ~90 minutes. Waking mid-cycle causes grogginess.

⏰ 5-6 options

Pick from 5 to 6 full cycles with realistic bedtime options.

🔢 Buffer aware

Accounts for the 10-20 minutes it takes to fall asleep.

🔖 Both directions

Plan from bedtime or from wake time, whichever you need.

More health tools

Sleep quality pairs with diet, hydration and activity trackers.