How to read the sleep chart
Find your target wake-up time in the left column, then pick a bedtime from the same row. Each suggestion counts back in 90-minute cycles and adds ~14 minutes to fall asleep, so your alarm lands at the lightest part of a cycle instead of deep sleep. The 6-cycle and 5-cycle columns (9 and 7.5 hours) are the sweet spot for most adults.
Need a different wake-up time, or want to adjust how long you take to fall asleep? The interactive sleep calculator handles any time and age. You can also check the recommended hours for your age or track how much rest you owe yourself with the sleep debt tracker.