Calculator What does the cousin relationship calculator identify?
The cousin relationship calculator names the cousin degree and the number of removals between two people. Count how many generations each person is below their closest shared ancestor, then enter both counts. For example, a shared grandparent is two generations above each grandchild, while a shared great-grandparent is three generations above. The cousin relationship calculator requires both counts to be at least two because direct ancestors, siblings, aunts, uncles, nieces, and nephews use different naming rules.
Choose the closest shared ancestor supported by the family tree. The calculation assumes each line descends independently from that person or ancestral couple. It does not search genealogy records or verify parentage. Its purpose is to translate two known generation counts into the conventional English cousin label.
How does the cousin relationship calculator formula work?
The cousin relationship calculator uses cousin degree = smaller generation count − 1. It uses removals = absolute difference between the generation counts. Equal counts produce no removal. A difference of one gives “once removed,” a difference of two gives “twice removed,” and larger differences use the number of times removed.
If both people are two generations below the shared ancestor, the result is first cousins. Counts of three and three return second cousins. Counts of three and five return second cousins twice removed because the smaller count establishes the second-cousin degree and the two-generation difference establishes the removal.
Cousin relationship calculator worked example
Person A is three generations below the closest shared ancestor and Person B is five generations below. The cousin relationship calculator finds min(3, 5) − 1 = 2, so the degree is second cousin. It then finds |3 − 5| = 2, so the complete English label is “second cousin twice removed.”
To check the result, draw one vertical line for each descent from the shared ancestor. The shorter branch reaches a great-grandchild after three steps; the longer branch needs five. The two extra steps explain the two removals. Use documented family relationships rather than estimated ages because generations can overlap widely.
What are the cousin relationship calculator limits?
The cousin relationship calculator assumes one closest shared ancestor path and does not resolve pedigree collapse, multiple cousin relationships, half relationships, adoption, marriage, or legal kinship. Two people can share more than one ancestral couple, especially in small or historically connected communities. In that case a single degree-and-removal label may not describe every genealogical connection.
It also does not predict an exact DNA percentage. Genetic inheritance varies, and relationship labels describe the family-tree path rather than proving biological descent. Use records, tested trees, and qualified genetic-genealogy guidance for evidence beyond the naming calculation.
How does the cousin relationship calculator compare with a cousin chart?
A printed cousin chart is useful when both generation counts are already visible. This tool applies the same row-and-column logic and states the result immediately. It is faster for testing several branches, while a chart can make the surrounding family structure easier to see.
The cousin relationship calculator is not an age calculator. Age differences do not determine cousin degree, because relatives in the same genealogical generation can be decades apart. Use the chronological-age calculator for elapsed calendar time and the cousin relationship calculator for descent from a shared ancestor.
Cousin relationship calculator questions
What should I count for the cousin relationship calculator?
Count parent-to-child steps from each person upward to the closest shared ancestor. A parent is one generation away, a grandparent two, and a great-grandparent three.
Can the cousin relationship calculator find siblings?
No. This tool starts at two generations per branch. If both people are only one generation below the shared parent, they are siblings and should not be entered as cousins.