Biorhythm Calculator
Calculate your physical, emotional, and intellectual biorhythm cycle values for any day, based on the pseudoscientific biorhythm theory.
Results
What is it?
For entertainment purposes only. Biorhythm theory proposes that human biological processes follow three sinusoidal cycles starting from birth: Physical (23 days), Emotional (28 days), and Intellectual (33 days). Positive values indicate a "high" phase; negative values indicate a "low" phase. The theory has no scientific support but remains popular in wellness culture.
How to use
Count the total number of days from your birth date to today (you can use an online date difference calculator). Enter that number in "Days Since Birth." Use "Days to Forecast" to see your cycles on a future or past date (e.g., +3 for three days from now). Values range from -100 to +100%.
Example scenario
A person 12,000 days old has Physical: +67%, Emotional: -45%, Intellectual: +12%. This hypothetically means today is a good day for physical activities but not the best for emotional decisions. Planning an important conversation might be better later in the week when the emotional cycle is positive.
Pro tip
Days when a cycle crosses zero (either direction) are called "critical days" in biorhythm lore � supposedly periods of instability. If two or three cycles cross zero on the same day, it's considered a "double" or "triple critical" day. These make for fun conversation starters, even if science disagrees with the premise.