Lift Up Your Hearts!

I never could keep cousins straight.  First cousins—the children of my parents' siblings—I understood, but I was lost when it came to second and third cousins, let alone those with the "removed" designation.  Not that I cared; it was rarely an issue for me.  When genealogy entered my life, however, family relationships suddenly needed to be a whole lot more specific.

After much puzzing over confusing definitions and tables, I gained enough head-knowledge to create the following algorithm.  My gut instincts in the matter are still a bit fuzzy, so I fall back on the strategy of the confused high school algebra student and rely on formulas.

To Calculate the Family Relationship Between Person A and Person B

Find C, the common ancestor between A and B.

Let N = the number of generations from A to C

Let M = the number of generations from B to C.

1. If N = 0, A is the (M – 2)^th great grandparent of B, where the 0^th great grandparent is defined as “grandparent,” the –1^st great grandparent is defined as “parent,” and the –2^nd great grandparent is defined as “self.”
2. If M = 0, A is the (N – 2)^th great grandchild of B, where the 0^th great grandchild is defined as “grandchild,” the –1^st great grandchild is defined as “child,” and the –2^nd great grandchild is defined as “self.”
3. If N = 1 and M > 0, then A is B’s (M – 3)^th great grandaunt/uncle, where the 0^th great grandaunt/uncle is defined as “grandaunt/uncle,” the –1^st great grandaunt/uncle is defined as “aunt/uncle” and the –2^nd great grandaunt/uncle is defined as “sister/brother.”
4. If M = 1 and N > 0, then A is B’s (N – 3)^th great grandniece/nephew, where the 0^th great grandniece/nephew is defined as “grandniece/nephew,” the –1^st great grandniece/nephew is defined as “niece/nephew” and the –2^nd great grandniece/nephew is defined as “sister/brother.”
5. If N > 1, M > 1, and N = M, then A and B are (N – 1)^th cousins.
6. If N > 1, M > 1, and N < M, then A and B are (N – 1)^th cousins, M – N times removed.
7. If N > 1, M > 1, and N > M, then A and B are (M – 1)^th cousins, N – M times removed.

It's a little nerdy—okay it's a lot nerdy—but it works for me, and I've never seen anything like it, so I post it here in case it may help someone else.