Couple biorhythms
Two births · six waves
Compare the physical, emotional and intellectual rhythm attributed to each date of birth. You will see which cycles move in step and which alternate. Names are optional, and the calculation happens here without storing either birth date.
Your synchrony map
Synchrony stays fixed because it depends on the distance between the two births. The curves below shift each day and show your combined energy over the coming month.
Highest combined energy
Three separate moments when the sum of all six waves reaches its highest values.
Lowest combined energy
Three separate moments when all six waves produce their lowest combined level.
How it is calculated
Synchrony is calculated from the correlation between two sine waves: 100% when they are in phase and 0% when they are completely opposed. The combined-energy dates add the level of all six waves and do not describe the quality of a relationship. Biorhythms have no scientific support; use this experience for entertainment and reflection, never as medical advice or a reason to make important decisions.
If each person carries three symbolic waves from the day they were born, comparing two birth dates produces six. This calculator asks one precise question: do the curves move together or in opposite directions? We call that cycle synchrony; it is not a measure of love, affinity or the quality of a relationship.
The score depends on the days between the two births. For each cycle, the phases of both waves are compared: when they coincide, synchrony is one hundred per cent; when they are completely opposed, it is zero. Values in between follow the actual correlation of the curves. That is why a couple's synchrony stays fixed: the distance between both dates does not change.
What does move every day is the position of all six waves. The app draws both paths — the first person as a solid line and the second as a dashed line — and looks across the coming month for separate moments of higher and lower combined energy. These are not good or bad days; they are simply the high and low points of the added curves.
A low synchrony score is not bad news either. Within the biorhythm idea, being out of phase simply means that two people do not pass through the same stretch at the same time. It can be read as alternation, but it cannot tell you how well you understand each other or how your relationship works.
Biorhythms emerged in the late nineteenth century, and these waves have never been shown to predict energy, health or behaviour. Use the result as entertainment and as an unusual way to look at the month ahead, never as a diagnosis or a reason to make an important decision.
If you like what comes out of two dates or two names, right next door are your own biorhythms, numerology compatibility and, if you would rather look at the sky, zodiac sign compatibility.