Chronotype Bedtime Calculator
Find a bedtime and wind-down time that fit your chronotype and target wake time, so you get a full night without fighting your body clock.
How it works
In-bed time = wake − sleep need − fall-asleep time · Wind-down = in-bed − 30 min · Fall-asleep time depends on chronotype
Chronotype describes when your body naturally wants to sleep and be alert, and it shifts how long you take to drift off once the lights are out. Rather than forcing a one-size bedtime, this tool works backward from your target wake time, adds your sleep need, and pads for a realistic fall-asleep window that runs longer for wolves and dolphins than for lions. Morning light, a dark cool room and a fixed schedule are the levers that let a night owl nudge an early wake time from painful toward workable.
Worked example
A bear wanting to wake at 6:30 AM with 8 hours of sleep and a 15-minute fall-asleep time should be in bed by 6:30 − 8:00 − 0:15 = 10:15 PM, and begin winding down (dim lights, no screens) around 9:45 PM.
Frequently asked questions
How do I know my chronotype?
Notice when you would naturally wake and feel sharpest with no obligations. Early-and-bright points to a lion, a mid-morning peak to a bear, evening energy to a wolf, and restless light sleep to a dolphin. Questionnaires like the morningness–eveningness scale formalise it.
Can I change my chronotype?
You can shift it modestly, not flip it. Bright morning light, consistent wake times and dimming screens in the evening move a late clock earlier over weeks. Genetics set the baseline you are nudging around.
Why pad for fall-asleep time?
Getting in bed is not the same as being asleep. If you need 8 hours of actual sleep and take 20 minutes to drop off, going to bed exactly 8 hours before your alarm quietly shorts you every night.
Related calculators
Educational estimate only — not medical advice, diagnosis, or treatment. Individual needs vary; consult a qualified healthcare professional for decisions about sleep, hydration, nutrition, exercise, or ergonomics.