Calculate your physical, emotional, and intellectual biorhythms based on your birthday.
This is an easy calculator designed to help anyone who wants to monitor their health or plan their well-being scientifically. The calculator works entirely in your browser – none of the information you enter is sent to the server, so you can use it with confidence.
The calculator is specifically aimed at anyone who wants to monitor their health or plan their well-being scientifically. It uses up-to-date values. The interface is designed to be as clear as possible: enter the required information into the fields and the result will be displayed immediately. The calculator is completely free and does not require registration.
Using it is simple. Enter the information requested by the calculator – such as income, expenses, dates, or other necessary starting values – and the calculator will automatically calculate the result. You can freely change the values and see the result update in real-time. All calculations are done with JavaScript code directly in your browser, so the calculator also works without an internet connection after it has been loaded.
The calculator is optimized for both desktop and mobile devices. You can use it on your phone, tablet, or computer. Dark and light modes are supported, minimizing eye strain during use.
The calculator is based on international scientific formulas and WHO recommendations. It does not replace the advice of a doctor or healthcare professional. If you have concerns about your health, please contact a healthcare professional.
The calculators are updated at least once a year – or immediately when there are changes to relevant guidelines or reference values. The calculators comply with international standards and guidelines.
You will get the best results by entering the values as accurately as possible. Try different scenarios – for example, how a small change in the starting values affects the final result. This way, you can make better decisions by comparing multiple options side by side. If you are unsure about a value, use a conservative estimate or seek information from an official source.
According to the biorhythm theory, three cycles vary as a sine wave throughout life from birth: physical (23 days), emotional (28 days) and intellectual (33 days). The calculator shows where you are in each cycle right now.
The biorhythm theory has not been validated by scientific research and is not considered a valid predictive method in current science. The calculator is intended for entertainment purposes out of curiosity, not for real-life decision-making.
The value of each cycle is calculated using the formula sin(2π × days lived ÷ cycle length), which gives a value between -100 % and +100 %. According to the theory, the zero points are the "most unstable" days, with extremes being either particularly good or weak.
The biorhythm theory assumes that from birth, three cycles – physical (23 days), emotional (28 days) and intellectual (33 days) – vary as a sine wave throughout life.
No. The biorhythm theory has not been validated by scientific research and is considered entertainment rather than a medical tool in current science.
Calculates the number of days from the birthday to today, and places the number into the sine function of each cycle (23, 28, and 33 days), resulting in the value of each rhythm between -100 % and +100 %.
A positive value is interpreted as a "good day" in that area according to the theory, while a negative value is considered "weaker". The zero points are, according to the theory, the most unstable days.
We recommend using the calculator for entertainment purposes only. There is no scientific evidence of its predictive value.