
Calculate the perfect bedtime or wake-up time based on 90-minute sleep cycles
A sleep calculator is a tool that helps you determine the optimal time to go to bed or wake up based on your body's natural sleep cycles. Instead of just counting hours, it calculates when you'll complete full 90-minute sleep cycles, which is the key to waking up feeling refreshed rather than groggy.
Why use it? Waking up in the middle of a deep sleep phase leaves you feeling tired, even if you slept for many hours. By timing your sleep to wake up between cycles (during light sleep), you'll feel more energized and alert. Our calculator accounts for the average 14 minutes it takes to fall asleep, giving you perfectly timed recommendations.

Good Night Lock helps you sleep better by automatically locking distracting apps during bedtime.
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