Relationship calculator
How it worksTo work out how you are related to someone, find the closest ancestor you both descend from, then say what that ancestor is to each of you. Choose both below and the calculator names the relationship, using the same rules and words as the Family Trees app.
Examples
- Your grandparent is their grandparent too: first cousins.
- Your great-grandparent is their grandparent: first cousin once removed.
- Your great-grandparent is their great-grandparent: second cousins.
- Your grandparent is their parent: they are your aunt or uncle.
For a whole family
In the Family Trees web app you don’t need to count. Add your family once and every person’s page says how they are related to you; How are they related? works for any two people, including step, half, adoptive, foster and in-law relations. Free for up to 100 people.
Questions
How do I calculate how I’m related to someone?
Find the nearest ancestor you share. Count generations from each of you up to that ancestor. The smaller count minus one is the cousin degree, and the difference between the two counts is how many times removed.
What if we share more than one ancestor?
Use the closest one. If you are related through two different lines, each line has its own relationship; Family Trees names the closest.