This sleep calculator counts back through 90-minute cycles to show the best times to fall asleep or wake up, so you rise between cycles.
To wake up refreshed, head to bed at:
These times factor in 15 minutes to fall asleep. Waking up between 90-minute sleep cycles prevents grogginess.
FAQs
Yes, you can find your wake times by entering your bedtime.
- Click "Calculate Wake Times."
The results show multiple options based on 90-minute sleep cycles. It assumes you take 15 minutes to fall asleep. - Click the "I'm going to bed at" tab.
- Select your exact bedtime from the time drop-down.
Yes, you can change the default 15-minute sleep onset delay.
- Move the slider to match your typical time.
- You can adjust this from 5 to 60 minutes. The calculator will immediately update your recommended times.
- Click the "Advanced Options" toggle switch.
- Find the "Time to fall asleep" slider.
Yes, you can use the tool for naps by selecting the "Power Nap" mode.
- Click the "Nap Mode" button next to the main calculator.
- Choose either "20 Min" or "90 Min" duration.
- The tool will give you a specific alarm time.
It only recommends 20 or 90 minute durations to prevent sleep inertia. It does not support custom nap lengths.