Family · Relationships
Cousin relationship calculator.
Pick how far up the family tree your shared ancestor is for you and for them. You get the cousin degree and the removal.
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How to work out cousin relationships
Find the closest ancestor you both descend from. Count the generations from you up to that ancestor, and from the other person up to the same ancestor. Cousins are separated from the ancestor by two or more generations.
- Degree is the smaller of the two counts, minus one: sharing grandparents makes you first cousins, sharing great-grandparents second cousins.
- Removal is the difference between the two counts.
Worked example. Your grandparent (2 generations up) is the other person's great-grandparent (3 generations up). The smaller count is 2, so the degree is 1, and the difference is 1: first cousin once removed. If you both go up 3 generations, it is a second cousin. Both going up 2 gives first cousins.
| Their ancestor is Grandparent | Their ancestor is Great-grandparent | Their ancestor is Great-great-grandparent | Their ancestor is Great-great-great-grandparent | |
|---|---|---|---|---|
| Your ancestor is Grandparent | First cousin | First cousin once removed | First cousin twice removed | First cousin 3 times removed |
| Your ancestor is Great-grandparent | First cousin once removed | Second cousin | Second cousin once removed | Second cousin twice removed |
| Your ancestor is Great-great-grandparent | First cousin twice removed | Second cousin once removed | Third cousin | Third cousin once removed |
| Your ancestor is Great-great-great-grandparent | First cousin 3 times removed | Second cousin twice removed | Third cousin once removed | Fourth cousin |
Per the standard English definition, siblings, aunts, uncles, nieces and nephews are not cousins. This is kinship naming only; it is not a genetic or legal relationship check.
Frequently asked questions
What is a first cousin once removed?
Your first cousin's child, or your parent's first cousin. For the older person, the shared ancestor is their grandparent and the younger person's great-grandparent.
What is the difference between second cousins and first cousins twice removed?
Second cousins share great-grandparents and are the same generation. First cousins twice removed are two generations apart: your grandparent is their great-great-grandparent.
How do I count removal?
Subtract the number of generations from one person to the shared ancestor from the other's. A difference of 1 is once removed, 2 is twice removed.
Are my parent's cousins my cousins?
A parent's first cousins are your first cousins once removed; their degree goes up with the parent's degree.
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Scope
For information and fun only. Not legal, medical or genealogical advice; rules about ages, eligibility and family relationships vary by place and program.