On days without alarms, note when you fall asleep and how long you sleep. The midpoint of that free sleep reveals your natural chronotype.
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- Risk spectrum with your position marked
- Reference ranges from the original publication
- Shareable link, nothing stored
Scientific references
What the midpoint shows
The center of sleep on free days tracks the internal clock more honestly than weekdays, when alarms and work distort timing. Early midpoints mean a morning type, late ones an evening type.
Reading the result
The answer is minutes after midnight. One hundred fifty is half past two, typical of morning types, while three hundred sixty, six in the morning, marks a strong evening type.
Understanding your result
- Under 150 minutes is a strong morning type
- 150 to 330 covers the intermediate majority
- Above 330 is a strong evening type
Using the knowledge
Schedule demanding work near your peak, protect light exposure timing, and accept that chronotype is largely genetic rather than a habit flaw.