đ´ Sleep Chronotype & Ideal Bedtime Calculator
Use your age, wakeâup time, and natural preferences to estimate your chronotype and get a realistic ideal bedtime window.
Last Updated: November 2025 ⢠Based on general sleepâduration guidelines from sleep foundations
Your Ideal Sleep Window
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recommended nightly sleep
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ideal bedtime window
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midâsleep (chronotype anchor)
How your chronotype and ideal bedtime are estimated
We combine your ageâbased sleep need range (for example, 7â9 hours for most adults) with your required wakeâup time and stated chronotype preference (morningâtype, flexible, or eveningâtype). We then:
- Pick a target sleep duration near the middle of your recommended range.
- Count backwards from your wakeâup time to get a core bedtime, then shift it slightly earlier for morningâtypes or later for eveningâtypes.
- Create a realistic bedtime window around that core time (Âą45â60 minutes).
If you enter your usual bedtime, we compare it with the ideal midpoint to estimate whether you are likely accumulating low, moderate, or high sleep debt. This tool is for education only and does not diagnose sleep disordersâtalk to a sleep specialist if you have persistent insomnia, snoring, or daytime sleepiness.
Understanding Your Chronotype
Your chronotype is your natural tendency to feel more alert in the morning or evening. Morning types (âlarksâ) wake up and get sleepy earlier. Evening types (âowlsâ) wake later and feel best later at night. Most people fall somewhere in between and can adapt either way with good routines.
Social schedules (school, work, family) often clash with our internal clock. When your required wakeâup time doesnât match your chronotype, you can build up âsocial jetlagââa mismatch similar to changing time zones every week.
Age and Sleep Needs
- Children 6â12 years: roughly 9â12 hours per night
- Teens 13â17 years: roughly 8â10 hours
- Adults 18â64 years: about 7â9 hours
- Older adults 65+: about 7â8 hours
These are rangesâyour personal best may be at the low or high end. The calculator uses the middle of the range as a starting point, then you can adjust based on how you feel.