What are biorhythms?

Biorhythms are wave-cycles which track the levels of our physical, emotional and intellectual energies. By entering your birth date into the biorhythm calculator above, you'll be able to calculate how well you're performing today using your biorhythm chart. The target date defaults to today's date, but you can also view your biorhythm chart for past and future dates as well.
The primary biorhythm cycles
The primary biorhythm cycles are the: "Emotional cycle", "Intellectual cycle" and "Physical cycle". Each of these three biorhythms oscillates at a different universal frequency starting on our date of birth.
Our physical cycles oscillate at roughly a 23 day cycle. Our emotional cycles are slightly longer, oscillating on a 28 day schedule. Our longest cycles are our emotional cycles which oscillate on a 33 day cycle. This concept of oscillating cycles is also used in natal astrology. The 23 day "physical" cycle is also sometimes referred to as a "male cycle" while the 28 day cycle is often referred to as a "female" cycle -- but both men and women are influenced by all biorhythm cycles.
By looking at your biorhythm chart, you'll be able to see how well you're performing on any given day, and what your potential (or lack of potential) may be. Your performance will be broken down into Emotional, Intellectual and Physical biorhythms.
Biorhythms are the cycles of our lives
Each of our biorhythm cycles moves at different rates which begin the day we are born. These cycles oscillate up and down at regular intervals throughout our lives. Each cycle moves up and down between "+100%" positive and "-100%" negative. The theory behind biorhythms is that the cycles move according to "sinusoidal" patterns.
These biorhythm waves measure human bio-electric energies which ebb and flow during the course of our lives. Because our biorhythm cycles move at different rates, we may have days where we are performing physically at optimum levels, but performing mentally at lower levels. On other days we may be functioning at peak intellectual levels but underperforming emotionally.
Biorhythms reveal good days and bad days
When a biorhythm crosses the 0% line, there is neither an added value or a reduced value to that attribute, however these "critical" days are considered to be erratic. Performance on "critical" (or 0%) days is unpredictable and may be characterized by random volatility. In other words: You can think of these 0% days as days when you're "neither here nor there" - you may have good moments, but you'll have plenty of bad ones too. Typically when we read biorhythm charts we look at the peaks and the lows of the biorhythm cycles, but these mid-range, or "0%" days can also tell an interesting story.
Primary biorhythm cycles vs. Secondary cycles
In addition to the 3 primary "Physical, Mental and Emotional" biorhythm waves there are an additional set of "secondary biorhythm cycles". This second set of biorhythm cycles are "composite calculations" which can give greater insight into more complex physical and emotional states. The secondary biorythm cycles are: "Wisdom", "Mastery" and "Passion".
Biorhythms and your love life
You can also use biorhythms for couples to measure the romantic and physical compatibility between two people on any given day. You can also use this to predict your romantic compatibility on any upcoming, future date. For more information about biorhythms and romance see our Biorhythms for Couples calculator.