Circadian Rhythm Analyzer
Answer 5 quick questions to estimate your chronotype, a likely sleep window, and your peak performance hours. A short, MEQ-inspired screen, updating live as you answer.
Pick one answer for each. The result updates as you go.
How to read this result
This is a short, MEQ-inspired self-report, not the validated Morningness-Eveningness Questionnaire (19 items, score 16-86) nor the validated reduced rMEQ (5 items, score 4-25). Its 5 custom questions and its band boundaries are heuristic and are not derived from a validated cut-score, so treat the chronotype, sleep window, and peak hours as an indication of your tendency, not a clinical classification. Higher score on this screen means more of an evening lean; lower means more of a morning lean (Horne & Ostberg 1976; Adan & Almirall 1991).
Frequently asked questions
What is a chronotype?
A chronotype is your body's natural inclination toward sleeping and waking at certain times. It is largely genetically determined and influences when you feel most alert, when you perform best cognitively, and when your body naturally wants to sleep. The three main chronotypes are morning type (early bird), intermediate type, and evening type (night owl).
Can I change my chronotype?
Your chronotype is largely genetic and cannot be fundamentally changed. However, you can shift your circadian rhythm by 1-2 hours through consistent light exposure, meal timing, and sleep scheduling. Chronotype also shifts naturally with age: teenagers tend toward eveningness, while older adults shift toward morningness (Roenneberg 2003).
What is social jet lag?
Social jet lag is the mismatch between your biological clock and your social schedule (work, school). For example, if you are an evening type forced to wake at 6 AM for work, you accumulate sleep debt during the week. It is common: up to ~87% of people show some degree of it in one Central-European study (Roenneberg, MCTQ sample), and it is associated with higher risk of obesity, depression, and cardiovascular disease.
When is the best time to exercise based on chronotype?
Morning types perform best with exercise between 07:00-11:00. Evening types peak between 17:00-21:00. Intermediate types are flexible but often do well around 10:00-14:00 or 16:00-18:00. Exercising near your peak alertness window maximizes performance and reduces injury risk.
Learn more
Related tools
- Horne JA, Östberg O (1976). A self-assessment questionnaire to determine morningness-eveningness in human circadian rhythms. Int J Chronobiol, 4(2):97-110. PubMed
- Adan A, Almirall H (1991). Horne & Östberg morningness-eveningness questionnaire: a reduced scale. Personality and Individual Differences, 12(3):241-253.
- Roenneberg T, Wirz-Justice A, Merrow M (2003). Life between clocks: daily temporal patterns of human chronotypes. J Biol Rhythms, 18(1):80-90. PubMed
- Knutson KL, von Schantz M (2018). Associations between chronotype, morbidity and mortality in the UK Biobank cohort. Chronobiol Int, 35(8):1045-1053. PubMed
- Windred DP et al. (2024). Sleep regularity is a stronger predictor of mortality risk than sleep duration. Sleep, 47(1):zsad253. PubMed
This was an estimate based on your answers. For precise, continuous tracking from real wearable data:
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