Quality sleep isn't just about hours — it's about cycles. Your brain moves through 90-minute sleep cycles each night, and waking up at the end of a cycle leaves you feeling refreshed and alert. Interrupting a cycle mid-way is what causes that groggy, heavy feeling known as sleep inertia. The Ideal Sleep Cycle Calculator takes your desired wake-up time and works backwards to give you the exact bedtimes that align with complete 90-minute cycles. Whether you're planning for 6, 7.5, or 9 hours of sleep, this tool helps you fall asleep at the right moment so every morning feels like a natural, energized start — not a rude interruption.
Wake up refreshed, every time
⏰ We'll add 15 minutes to fall asleep