Two dates of birth, the relationship type, and a reading of your compatibility today.
Privacy first. Mathematical calculation on biological cycles of 23, 28 and 33 days.
The test calculates permanent compatibility between two people starting from the difference between their birth dates, across three biorhythms: physical, emotional and intellectual. The calculation returns three percentages from 0 to 100, one for each biorhythm, and an overall result obtained as their simple arithmetic mean. These values remain constant over time. The relationship type selected personalises the interpretation of the results without changing the calculation or the percentages. The test is instant and needs no registration: two birth dates and the type of relationship are enough.
With Premium you can go deeper through the “Biorhythm Comparison” feature, which lets you observe how each person’s three biorhythms move on a specific date or over a period. The six cycles change position over time, while permanent compatibility stays the same.
Physical energy, vitality, strength, endurance, initiative and rhythm in shared activities.
Sensitivity, affection, empathy, emotional reactions, mutual understanding and harmony in feelings.
Thought, reasoning, ideas, communication, mental rapport and the ability to make shared decisions.
In the glossaryPhysical cycleEmotional cycleIntellectual cycleDouble critical day
The overall percentage gives a summary of permanent compatibility, but it does not tell the whole story. Two couples can get the same average and show very different combinations across the three biorhythms: physical, emotional and intellectual. It is reading the individual values that helps you understand how the result is made up.
Indicates a greater degree of correspondence between the two people’s cycles, according to the biorhythm model. A high value in one of the three biorhythms means greater compatibility in that specific dimension, without necessarily guaranteeing a good understanding in the relationship.
Indicates a lower degree of correspondence between the two people’s cycles in the dimension considered. It is not a negative judgement and does not determine incompatibility in real life, but it highlights a difference within the calculation model.
Not all couple compatibility tests use the same method. To grasp what they mean, it is important to tell the different approaches apart, understand how the results are produced and what interpretation can be given to the values obtained.
At byourit, the compatibility calculation starts from the difference between two people’s birth dates and the three biorhythmic cycles of 23, 28 and 33 days. The result includes three permanent compatibility percentages (physical, emotional and intellectual) and an overall percentage obtained as their simple arithmetic mean. These values remain constant over time. The Biorhythm Comparison feature, instead, lets you observe how the positions of the two people’s six cycles change day after day, without altering their permanent compatibility. The percentages express the values predicted by the biorhythm model, not direct measurements of people’s physical, emotional or intellectual condition or of the quality of their relationship.
Starts from the position of the planets at birth. It needs the exact hour, it shifts with the tradition you follow, and it works if you believe in it. A legitimate choice, but a different one. The full comparison.
They count the letters in your names. Change a nickname and the percentage changes. A pastime, and nobody claims otherwise.
Compatibility between two people is permanent. The three percentages (physical, emotional and intellectual) derive from the difference between their birth dates and stay constant over time, as does their overall average. Age, stress, habits and personal circumstances can affect daily life and the relationship, but they do not change the compatibility values predicted by the biorhythm model. The Premium Biorhythm Comparison feature instead lets you observe, on a specific date or over a given period, how each person’s three biorhythms move: six cycles in all. Their positions change as the days go by, while the permanent compatibility percentages stay unchanged. Repeating the permanent compatibility test between the same two people therefore returns the same values. To see how their biorhythms look at different moments, you can use Biorhythm Comparison, without confusing this time-based analysis with the permanent compatibility result.
To learn more: When a low score is not a problem.
byourit calculates permanent compatibility between two people through three biorhythms: physical, emotional and intellectual. The overall result is the simple arithmetic mean of the three percentages and stays constant over time. The free version lets you see the overall compatibility and receive a first interpretation adapted to the selected type of relationship. With Premium you can explore the three dimensions of permanent compatibility in depth and use the Biorhythm Comparison feature, which lets you observe how the six cycles of the two people move on a specific date or over a period. The interpretations offer food for reflection; they do not directly measure relationship quality or predict its outcome. Some Premium content may be produced with the support of artificial intelligence, as described in the privacy policy.
To better understand the meaning and limits of these analyses, read the guide What a compatibility test is not meant for.
The calculation is reproducible, but the fixed three-cycle theory is not supported by the empirical validation reviewed in our sources. Use readings as personal prompts, not as diagnoses, predictions or measurements of your abilities or relationships. The historical sources, including the critical ones.
