Chronotype Sleep Preference Calculator
Determine your chronotype (morning lark, intermediate, or night owl) and find your ideal sleep and wake times based on your natural rhythm.
What Is a Chronotype? Your chronotype is your innate biological preference for when to sleep and wake. It is primarily determined by genetics and gradually shifts over your lifetime. Children tend to be morning types. Teenagers shift toward evening types. Adults gradually shift back toward morning types with age.
The Science Chronotype is linked to your circadian clock — the roughly 24-hour internal rhythm driven by the suprachiasmatic nucleus (SCN) in the brain. Your circadian clock regulates body temperature, hormone release (especially melatonin and cortisol), alertness, and performance.
Types
- Morning Type (Lark): Naturally early to bed and early to rise. Peak cognitive performance in the morning.
- Intermediate Type: The majority of people. Flexible sleep timing.
- Evening Type (Owl): Naturally late to sleep and late to wake. Peak performance in the afternoon or evening.
Why It Matters Working against your chronotype leads to “social jetlag” — a chronic mismatch between your internal clock and your schedule. Social jetlag is associated with increased fatigue, poor performance, metabolic effects, and mood disruption.
This Calculator Uses a simplified scoring approach based on validated chronotype questionnaires (MEQ — Morningness-Eveningness Questionnaire).