What is a first cousin once removed?
Short answerYour first cousin once removed is either your parent’s first cousin or your first cousin’s child. “First cousin” comes from whichever of you is closer to the shared ancestors; “once removed” means you are 1 generation apart. The word is the same in both directions: you are their first cousin once removed too. Full first cousins once removed share about 6.25% of their DNA on average.
The family line, drawn out
Follow the highlighted line from you up to the shared ancestor and down to them.
How to work it out
- Find the nearest ancestor you share: your great-grandparent.
- Count the generations from each of you up to that ancestor: 3 for one, 2 for the other.
- Take the smaller number and subtract one: 2 − 1 = 1, so they are first cousins.
- The difference between the two numbers is how many times removed: 3 − 2 = 1.
Cousins are only “removed” when they belong to different generations. Two people in the same generation are never removed, whatever their ages.
Their family and yours
Relationships shift by one step for each generation. Here is how the people around them relate to you:
| Their child | second cousin |
| Their parent on the shared line | great-aunt or uncle |
| Your child sees them as your child’s | first cousin twice removed |
| Your parent sees them as your parent’s | first cousin |
| What they call you | first cousin once removed |
Shared DNA
On average, full first cousins once removed share about 6.25% of their DNA. That figure is the expected value: it halves with every generation of separation, and real amounts vary from person to person. A half relationship (through only one shared ancestor instead of a couple) shares about half as much: 3.12%.
Let Family Trees name it for you
In Family Trees, open anyone’s page to see how they are related to you in plain words, or choose any two people under How are they related?. The app counts the shortest blood line through birth and adoptive parents, names step, foster and in-law relations too, and uses exactly the words on this page. It’s free for a family of up to 100 people. You can also try the relationship calculator here.
Questions
What is a first cousin once removed?
Your first cousin once removed is either your parent’s first cousin or your first cousin’s child. “First cousin” comes from whichever of you is closer to the shared ancestors; “once removed” means you are 1 generation apart. The word is the same in both directions: you are their first cousin once removed too.
How much DNA do you share with a first cousin once removed?
About 6.25% on average. Each generation of separation halves the expected amount, and individual results vary.
What is my first cousin once removed’s child to me?
Your second cousin.
Is a first cousin once removed the same as a second cousin?
No. A second cousin is in your own generation and shares your great-grandparents. A first cousin once removed shares the same ancestors but sits 1 generation away from you.