👪 Cousin Relationship Calculator
Enter how many generations back each person is from their shared common ancestor to find the exact cousin relationship between them.
Degree and removal are two separate counts
Count each person's generations down from the ancestor they share, where 1 means a child of that ancestor, 2 a grandchild, 3 a great-grandchild. The tool then applies two rules that between them settle every cousin relationship:
cousin degree = min(A, B) - 1
times removed = |A - B|Work through second cousin once removed. Second cousins share a set of great-grandparents, so you are 3 generations down. Your second cousin's daughter is 4 down from those same people. Degree is min(3, 4) − 1 = 2, and removal is |3 − 4| = 1, giving second cousins once removed. Enter 3 and 4 and that is what comes back.
Common pairs to check yourself against
| A | B | Degree | Removed | Relationship |
|---|---|---|---|---|
| 1 | 1 | 0 | 0 | Siblings |
| 1 | 2 | 0 | 1 | Aunt or uncle to niece or nephew |
| 1 | 3 | 0 | 2 | Great-aunt or great-uncle |
| 2 | 2 | 1 | 0 | First cousins |
| 2 | 3 | 1 | 1 | First cousins once removed |
| 3 | 3 | 2 | 0 | Second cousins |
| 4 | 4 | 3 | 0 | Third cousins |
Frequently asked questions
Is my cousin's child my second cousin?
No. Enter 2 and 3 and you get first cousin once removed. Your children and your cousin's children are the second cousins, both being 3 generations from the shared great-grandparents.
What generations do I enter for my great-aunt?
1 for her and 3 for you, since she is a daughter of your great-grandparents and you are their great-grandchild. Degree 0 with two removals is read as a great-aunt, not as a cousin.
Do double cousins change the answer?
Not the label. Two siblings marrying two siblings gives children who are first cousins through both couples, so they stay first cousins here but share about twice the usual DNA.