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Biorhythm Calculator

Enter your birth date to see today’s biorhythm and the 15 days around it. Please treat it as entertainment.

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Days since birth
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Physical
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Emotional
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Intellectual
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7 days from the chosen date

DatePhysicalEmotionalIntellectual

Biorhythm theory has no scientific support. Enjoy it for fun, and do not base health or important decisions on it.

How to use

  1. With t as the number of days since birth, each cycle is sin(2π × t ÷ period) × 100. The periods are 23 days (physical), 28 (emotional) and 33 (intellectual).
  2. Enter your date of birth. The date is set to today; change it or step one day at a time with the arrows.
  3. Hover over the chart or tap it to read all three values for that day. Above zero is read as a high phase, below zero as a recharge phase.
  4. Days when a cycle crosses zero are traditionally called critical days. The table lists the next seven days and flags them.

FAQ

Is there any science behind biorhythms?

No. The idea dates from the late 19th century, and studies have found no meaningful link with accidents, performance or mood. It is best enjoyed as a pastime.

What is a critical day?

It is a day when a cycle switches between positive and negative. Biorhythm theory calls these unstable days, but this has never been shown scientifically.

Does my time of birth matter?

No. Only calendar dates are used, and the day count is the plain difference between dates, unaffected by time zones or daylight saving.

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