Compatibility by the Pythagorean Square
Two birth dates become a pair of squares, a symbolic score and a reading about the patterns you share. No birth time or place needed.
How the Pythagorean Square works
The square counts the digits in your birth date and four additional numbers. Repeated digits fill nine cells, and the totals across eight lines provide themes for a comparison.
The first number is the sum of all date digits. The second adds the first number’s digits once. For the third, subtract twice the first digit of the birth day, without a leading zero, from the first number and take the absolute value. The fourth adds the third number’s digits once. Ignore zeros when filling the square. The same rules apply before and after 2000.
A worked example
For 12 March 1985, the four additional numbers are 29, 11, 27 and 9. The square contains 1111, 222, 3, an empty 4 cell, 5, an empty 6 cell, 7, 8 and 999.
What the percentage means
The percentage is Coeluna’s playful comparison of the eight line patterns. It does not measure love or predict a relationship’s future. Other calculators can use different conventions.
Line totals fall into five levels: 0, 1–2, 3–4, 5–6 and 7 or more. Each line starts at 90 points, with 15 taken off for each level of difference. Two empty lines receive 50 and two very full lines receive 70. The rounded average is your symbolic score.
Read it alongside real life
Empty cells do not mean missing abilities. A strong pattern is not automatically better. Use the reading to compare preferences and start a conversation; your experience matters more than the numbers.
Questions
How do I calculate Pythagorean Square compatibility?
Enter two birth dates and choose Read your connection. The calculator creates both squares and composes a reading from their actual shared patterns and differences.
Do I need a birth time or birthplace?
No. Only two birth dates are needed. Names are optional and simply help identify each square.
Is this a scientific compatibility test?
No. This is symbolic numerology for reflection. The percentage is a transparent Coeluna heuristic, not evidence that a couple should stay together or separate.
What is included when I share?
A shared link contains the birth dates and optional names so the recipient can recreate the reading. The image omits birth dates. Sharing is optional, and no account is needed.
Does the formula change for births after 2000?
No. We use one fixed calculation for every supported date, including absolute differences and a single digit-sum step for the second and fourth additional numbers.