Physical
The shortest cycle in the traditional model, associated with energy, strength, and coordination.
Cycle explorer toy
Biorhythm Calculator
Plot physical, emotional, and intellectual cycles around any date. Your birth details stay in this browser.
Birth details
Set your starting point
The chart refreshes as soon as you change a value.
Cycle chart
Your rhythm at a glance
Center line: today
Physical
Emotional
Intellectual
Total
Astral hell
Values above the middle line are positive phases; values below it are negative phases.
The four curves
Read each cycle separately
The classic three cycles have different periods, so their waves continually move in and out of alignment.
Emotional
Traditionally associated with mood, sensitivity, creativity, and emotional awareness.
Intellectual
The longest classic cycle, associated with attention, memory, reasoning, and learning.
Total
An optional average of the three curves that makes their general highs, lows, and crossings easier to spot.
How it works
Reading the waves
Biorhythm theory proposes that several repeating cycles begin at birth. Because the periods have different lengths, the curves diverge and reconverge over time.
Followers of the theory pay particular attention to crossing days, when a curve passes through the center line. Double and triple crossings happen when two or three cycles transition close together.
The shaded birthday window, traditionally called “astral hell,” covers the month leading up to the nearest birthday.
The calculator code is open for study. Republishing it on other sites is not permitted.