Biorhythm Calculator

What Are Biorhythms?

Biorhythm theory proposes that our lives are affected by three fundamental biological cycles that begin at birth and continue in fixed sine-wave patterns throughout life. The concept was developed in the late 19th century by Wilhelm Fliess, a German physician, and later popularized by Hermann Swoboda and Alfred Teltscher in the early 20th century.

The three primary biorhythm cycles are: Physical (23 days), which affects strength, coordination, and physical well-being; Emotional (28 days), which influences mood, creativity, and sensitivity; and Intellectual (33 days), which governs analytical thinking, logic, and memory. Each cycle follows a sine wave pattern, oscillating between positive (peak) and negative (low) phases.

The Three Biorhythm Cycles

• Physical Cycle (23 days): Governs your physical energy, strength, endurance, resistance to illness, and coordination. During peak phases, you may feel more energetic and physically capable. During low phases, rest may be more important.
• Emotional Cycle (28 days): Influences your mood, emotional stability, creativity, and sensitivity. High phases bring emotional positivity and creative inspiration. Low phases may bring moodiness or emotional sensitivity.
• Intellectual Cycle (33 days): Affects your cognitive abilities, concentration, memory, and analytical thinking. Peak phases favor complex mental tasks, while low phases may require more effort for intellectual work.

How to Read Your Biorhythm Chart

• Above the center line (positive): You are in a high phase — expect favorable conditions for that cycle.
• Below the center line (negative): You are in a low phase — take extra care in activities related to that cycle.
• Crossing the center line (critical days): These transition days are considered the most significant — you may feel unstable or unpredictable in that area.
• Near the top (100%): Peak performance — your best days for that cycle.
• Near the bottom (-100%): Lowest point — rest and recharge.

Scientific Perspective

It is important to note that biorhythm theory is not supported by mainstream science. Multiple studies have failed to find evidence that these fixed cycles accurately predict human performance or behavior. The human body does have real biological rhythms (circadian rhythms, for example), but they do not follow the fixed 23/28/33-day patterns proposed by biorhythm theory. That said, many people enjoy tracking their biorhythms as a tool for self-awareness and reflection.