How can you find out your circadian rhythm?

Short answer: You can get a good picture at home in one to two weeks. Fill in a short chronotype questionnaire, keep a simple diary of sleep and daylight, and look at the timing of your steps if a phone or watch records them. Together these show whether your body clock runs early or late, and how steady it is from day to day.

Is there a body clock test you can take at home?

Yes, and the most common ones are questionnaires. The Morningness-Eveningness Questionnaire, published by Horne and Östberg in 1976, is a self-assessment that places you as a morning type, an evening type or in between. In their original group of 48 people, morning types went to bed and got up earlier than evening types, and their body temperature peaked earlier in the day.

The Munich ChronoType Questionnaire asks instead when you actually sleep on work days and on free days, and it uses the midpoint of your sleep on free days as your chronotype. In a Dutch survey of 2,481 people who filled in both, the two questionnaires agreed well.

How can you check your circadian rhythm for free?

Keep a diary, which costs nothing and shows patterns over many days. For one to two weeks, write down when you go to bed, when you wake in the night and when you get up, along with caffeine, alcohol and exercise. The National Institute on Aging suggests this kind of diary, kept for a couple of weeks, if you have trouble sleeping.

Add light to it. Note roughly how long you spend outdoors in daylight each day, because in a survey of 500 people, more time in daylight went with earlier sleep for every chronotype. Keep free days in the diary too, because chronotype researchers use sleep on free days, without work or social obligations, as the reference point.

How can you determine your circadian rhythm from a phone or watch?

Use its step data as an automatic record of when you move and when you rest:

• Doctors who look at sleep-wake cycles may ask you to wear a small motion sensor for 3 to 14 days.
• A phone or watch that counts steps keeps a similar record of when you are active and when you are still.
• Look at one to two weeks together, not a single day: when your active hours start and end, how much that varies, and whether free days run later than work days.

A doctor can go further and repeatedly measure body temperature and hormone levels in blood or saliva, which shows how they rise and fall over the day. For what consumer devices can and cannot see, read whether a smartwatch or phone can track your circadian rhythm.

How do you know your circadian rhythm type from the results?

Put the questionnaire, the diary and the step data side by side. If the questionnaire says evening type, your free-day sleep runs late and your steps start late, the picture is consistent. Most people fall somewhere between the extremes, and chronotype also shifts with age.

A large gap between work days and free days is worth noticing. In the 500-person pilot of the Munich questionnaire, sleep times differed a lot between work days and free days for everyone except extreme early types. Late types built up sleep debt during the week and slept several hours longer on free days, a pattern explained in what social jet lag is. For more on the types themselves, see what a chronotype is.

How Actogram looks at this

Actogram focuses on the phone and watch method. It reads the daily rhythm of rest and activity from ordinary minute-level step counts, and it needs no heart rate and no sleep stages. It reads the rhythm from the daytime activity pattern, not only from night sleep.

The method was tested on existing data from about 30,000 participant samples, from the US NHANES health survey and Fitbit. Its tools are for research and wellness use and do not diagnose, treat or prevent any condition.

Sources

• A self-assessment questionnaire to determine morningness-eveningness in human circadian rhythms, International Journal of Chronobiology, 1976
• Comparison of the Munich Chronotype Questionnaire with the Horne-Ostberg's Morningness-Eveningness Score, Chronobiology International, 2005
• Life between clocks: daily temporal patterns of human chronotypes, Journal of Biological Rhythms, 2003
• A marker for the end of adolescence, Current Biology, 2004
• Sleep and Older Adults, National Institute on Aging, 2025
• Circadian Rhythm Disorders, National Heart, Lung, and Blood Institute, 2022

General information, not medical advice. If sleep or tiredness problems affect your daily life, talk to a doctor. Reviewed 6 November 2026 by the Actogram team.