Biorhythm Calculator
Chart your physical, emotional and intellectual cycles with the traditional biorhythm model, from your birth date to any date you choose.
What the traditional biorhythm model is
The biorhythm model proposes three sine-wave cycles with fixed periods — 23 days (physical), 28 days (emotional) and 33 days (intellectual) — starting on your birth date. It's a traditional model, popularized since the late 19th century, with no validated scientific backing: here it's presented as exactly that, a curious mathematical calculation over those cycles.
How to read the chart
Each curve oscillates between -100% and +100%. A value near +100% is traditionally read as a high point of that cycle; near -100%, a low point; and the crossing through 0% as a transition day.