Your biological age is an estimate of how old your body actually is on the inside — which can be very different from the number of birthdays you have had. This free biological age calculator gives you two ways to find out. The Quick mode takes about 60 seconds and uses only your everyday habits, […]
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July 10, 2026
Chronotype Calculator — Are You a Lark or a Night Owl?
July 10, 2026
Your body has its own clock — and it doesn’t always agree with your alarm. Some people are wired to rise early and fade by evening; others don’t hit their stride until later and would happily sleep in. That internal timing is your chronotype, and the gap between it and your work schedule is your “social jet lag.” Enter your typical sleep times on work days and on free days (when you wake without an alarm), and this calculator finds both, using the Munich ChronoType method.
It’s a self-report estimate, and nothing is stored.
Longevity Centers of America
Chronotype & Social Jet Lag
Lark or owl? And how far is your body clock from your alarm clock?
Enter your typical sleep times on work days and on free days (when you sleep without an alarm). We’ll find your chronotype and your “social jet lag” — the gap between your natural rhythm and your schedule — using the Munich ChronoType method.
Work / School Days
Free Days (no alarm)
Please enter all four sleep and wake times.
Your Chronotype
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◀ Early birdNight owl ▶
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Sleep midpoint (free)
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Social jet lag
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Avg sleep / night
We Listen. We Test. We Heal.
Your body clock shapes your energy, hormones, and recovery. Aligning your schedule with it — and testing what’s underneath — is real longevity work.
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Chronotype is estimated as the sleep-corrected midpoint of sleep on free days (MSFsc) from the Munich ChronoType Questionnaire method (Roenneberg T, Wirz-Justice A, Merrow M, “Life between clocks: daily temporal patterns of human chronotypes,” J Biol Rhythms, 2003). Mid-sleep is the clock time halfway between falling asleep and waking; on free days it is corrected for sleep you “catch up” relative to your weekly average. Social jet lag is the difference between mid-sleep on free versus work days (Wittmann M, et al., “Social jetlag: misalignment of biological and social time,” Chronobiology International, 2006). Categories here are approximate, based on population distributions; this is a self-report estimate, not a clinical measurement.
For educational and wellness purposes only. This is a self-report estimate of your circadian timing, not a diagnosis or medical advice. Sleep needs and rhythms vary by individual and change with age. These statements have not been evaluated by the FDA. If you have ongoing problems with sleep, energy, or mood, please consult a licensed healthcare provider.
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Free Chronotype Calculator by Longevity Centers of America
What is a chronotype?
Your chronotype is the natural timing of your body clock — when it wants you to sleep and wake. It’s why “larks” (early types) and “owls” (late types) exist. Chronotype isn’t a personality choice; it’s largely driven by your internal circadian rhythm, shaped by genetics, age, and light exposure. And it isn’t two boxes — it’s a spectrum, with most people somewhere in the middle and a smaller number at the strongly early or strongly late ends.
What is social jet lag?
Social jet lag is the mismatch between your body clock and your social schedule. If your natural rhythm wants you asleep until 8 but work demands 6, your body effectively lives in a different time zone from your calendar — and you “travel” back and forth every week. It’s measured as the difference between the midpoint of your sleep on free days versus work days (Wittmann et al., 2006). Larger gaps are common in late types on early schedules, and research has linked greater social jet lag to poorer metabolic and mood outcomes — which is why closing the gap is worth the effort.
How is chronotype measured?
The key number is your mid-sleep time on free days — the clock time exactly halfway between falling asleep and waking, measured on days when you’re not woken by an alarm. Free days are used because they reveal your biological timing without your work schedule masking it. That midpoint is then corrected for any “catch-up” sleep you get on free days, producing the standard chronotype marker (MSFsc) from the Munich ChronoType method. Because an alarm hides your true wake time, the free-day answers should reflect waking up naturally.
Why does your body clock matter?
Circadian timing influences far more than when you feel sleepy — it shapes energy, focus, hormone release, appetite, and recovery across the day. Living chronically out of sync with your clock (high social jet lag) has been associated with worse sleep, low daytime energy, and metabolic strain. Aligning your schedule with your biology, even partway, tends to pay off in how you feel and function.
How to reduce social jet lag
You usually can’t flip a night owl into a lark, but you can narrow the gap:
- Get morning light. Bright light early in the day nudges your clock earlier and is the most powerful lever you have.
- Keep wake times consistent. A steady wake time — even on weekends — does more to stabilize your clock than a steady bedtime.
- Dim the evening. Lower light and less late screen exposure make it easier to fall asleep earlier.
- Shift gradually. Move bedtime and wake time by 15–30 minutes at a time rather than all at once.
About this calculator
This tool uses the Munich ChronoType method (Roenneberg et al., 2003): your chronotype is estimated from the corrected midpoint of your sleep on free days, and your social jet lag from the difference between your free-day and work-day sleep midpoints. It’s a self-report estimate based on population patterns, not a clinical measurement — useful for insight and for guiding small, consistent adjustments.
Frequently Asked Questions
What is a chronotype?
Your chronotype is the natural timing of your internal body clock — when it wants you to sleep and wake. It’s why some people are early “larks” and others are late “owls,” and it sits on a spectrum shaped by genetics, age, and light.
What is social jet lag?
Social jet lag is the mismatch between your body clock and your social schedule. It’s measured as the difference between the midpoint of your sleep on free days and on work days — like commuting across time zones every week without leaving home.
How do I find my chronotype?
Look at your sleep on days without an alarm. The midpoint between when you fall asleep and wake up on free days — corrected for catch-up sleep — is the standard chronotype marker. Earlier midpoints lean lark, later ones lean owl.
What is a normal amount of social jet lag?
Many people have roughly 1 to 2 hours. Two hours or more is a meaningful, recurring mismatch that’s worth narrowing, since chronic misalignment is linked to worse sleep and metabolic strain.
Can you change your chronotype?
Partly. You can’t turn a strong night owl into a lark, but morning light, consistent wake times, and dimmer evenings can shift your timing earlier and reduce social jet lag. Chronotype also naturally moves earlier as you age.
Is being a night owl unhealthy?
Being an owl isn’t unhealthy by itself. The bigger issue is the misalignment — owls forced onto early schedules accumulate more social jet lag, which is what’s been associated with poorer health outcomes.
Does chronotype change with age?
Yes. Children tend to be early, timing shifts markedly later through the teens and early twenties (the latest chronotypes on average), and then gradually moves earlier again through adulthood.
How can I reduce social jet lag?
Anchor a consistent wake time (even on weekends), get bright light in the morning, dim lights and screens in the evening, and shift your schedule gradually in 15–30 minute steps.
Kyle Hulbert is the co-founder and operator at The Longevity Centers of America, which he built alongside Dr. Kosubevsky with the mission to drastically improve the lives of millions of people. Drawing on his own transformation as a patient, he designed the practice around accessibility, affordability, and focus on data-driven regenerative care for individuals who have been underserved by conventional medicine. His background bridges academic rigor and practical application. Hulbert holds bachelor's and master's degrees in business administration, is a doctoral trained researcher, and has carried credentials as a Certified Wellness Coach, Certified Nutrition Coach, and Certified Personal Trainer, all through the National Academy of Sports Medicine, as well as an Integrative Nutrition Coach certification from the Institute for Integrative Nutrition and a Dietary Supplement Specialist designation through the Designs for Health, a trusted leader in science-backed wellness solutions. Hulbert also co-hosts a weekly podcast, "Longevity Unlocked," with Dr. Kosubevsky, translating emerging research on detoxification, hormonal health, and regenerative therapies into real-world discussion to better educate individuals about their health.
About Kyle Hulbert
