Numbers & cycles
Biorhythm
Track your physical, emotional and intellectual cycles for any date, on the classic 23 / 28 / 33-day biorhythm model.
Enter your details below to compute your result.
Biorhythm theory models three cycles that begin at birth. One runs 23 days and governs the physical, one runs 28 days for the emotional, and one runs 33 days for the intellectual. Each rises and falls as a sine wave. Enter your birth date and any target date to see where each cycle sits, and whether the day counts as high, low or 'critical' (a zero crossing).
It's a light, self-reflective tool, computed entirely in your browser.
How to read your result
Positive percentages are the high (energised) half of a cycle; negative are the low (recharge) half.
'Critical' days are when a cycle crosses zero, traditionally seen as unstable for that area.
How it's calculated
For each cycle, value = sin(2π × days-since-birth ÷ period), shown as a percentage from −100% to +100%.
See this inside your full Kundali
This is one section of your birth chart. Generate the complete free Kundali, with charts, dashas, doshas, panchang and more.
Frequently asked questions
What are the three biorhythm cycles?
Physical (23 days), emotional (28 days) and intellectual (33 days). Each is modelled as a sine wave starting from your birth date.
What is a critical day?
A day when a cycle crosses the zero line between its high and low halves. It is considered the most changeable day for that cycle.
Is biorhythm scientific?
No. Biorhythms are a popular self-reflection model, not a scientifically validated predictor. Use it for fun and reflection.