Calcometry

Family Relationship Calculator

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Generations from each person to the same ancestor → cousin degree and removal label.

Generations to shared ancestor

Relationship

2nd cousin

Your closest shared ancestor is 3 generation(s) up for the nearer person — 2nd cousin.

Person A generations
3
Person B generations
3

Related calculators

Cousin degree and removal

Genealogists describe how two people relate by counting generations up to their most recent common ancestor (MRCA). Each step up is one generation: parent = 1, grandparent = 2, great-grandparent = 3, and so on.

When both people are the same number of generations from the MRCA, they are nth cousins where n = generations minus one (same grandparent → 1st cousins; same great-grandparent → 2nd cousins). When the counts differ, add "once removed," "twice removed," etc. for each extra generation on one side.

Example: both 3 generations from a shared great-grandparent → 2nd cousins. Person A is 2 generations up (grandparent level) and Person B is 3 → 1st cousin once removed. Step-siblings, in-laws, and half-relations need family context this chart does not capture.

Common questions

What does "generations to shared ancestor" mean?

Count upward from each person to the same ancestor: 1 = parent, 2 = grandparent, 3 = great-grandparent. Both people must share that exact ancestor.

Does this cover in-laws or step-family?

No. This tool only handles blood-line cousin math from a shared ancestor. In-law and step labels depend on marriage and household structure, not generation counts alone.

How is this different from the generation calculator?

Generation calculator maps a birth year to a social cohort (Gen Z, Millennial, etc.). This tool labels kinship between two people from genealogy generation counts.