A free, beautifully designed tool to help you understand your natural physical, emotional and intellectual energy cycles.
Biorhythm Calculator is a free online tool dedicated to helping people understand the natural rhythmic cycles that govern their daily energy, mood and mental clarity. We believe that self-awareness is the foundation of a well-lived life — and that understanding your own rhythms is one of the most practical forms of self-knowledge available.
Our calculator is built on the biorhythm theory developed by Wilhelm Fliess and Hermann Swoboda in the late 19th century, and refined by Alfred Teltscher in the 1920s. We have taken this classical framework and presented it through a modern, beautiful and entirely free interface — accessible to anyone, anywhere, on any device.
Our mission is simple: to give everyone free access to a beautifully designed, accurate and easy-to-use biorhythm calculator — with no ads cluttering the experience, no signup required, and no data stored on our servers.
We want every person who visits our site to leave with a clearer understanding of their own natural energy patterns, and a practical tool they can return to daily to make better decisions about how to spend their time and energy.
Free forever. Our core biorhythm calculator will always be completely free to use with no registration required.
Privacy first. Your date of birth is processed entirely in your browser. We never store personal data on our servers. Read our full Privacy Policy for details.
Always improving. We are continuously adding new features, content and tools to help you get the most from your biorhythm readings.
Have a question, suggestion or feedback? We would love to hear from you. Visit our contact page to send us a message. We read every message and respond as quickly as possible.