Family Relationship Calculator
What is your cousin’s child to you? Build the relationship one step at a time - your mother’s cousin’s daughter, your grandmother’s sister - and get its proper name, from second cousin once removed to great-aunt.
Who Are They to You?
Describe them one step at a time, the way you’d say it - for example mother, then cousin, then daughter.
Or try one of these: , , , ,
Cousin Chart
Find the closest ancestor you both descend from. Take the row for how you descend from them and the column for how they do - where the two meet is your relationship.
| You ↓ / Them → | Shared ancestor | Child | Grandchild | Great-grandchild | Great-great-grandchild | 3x great-grandchild |
|---|---|---|---|---|---|---|
| Shared ancestor | - | Child | Grandchild | Great-grandchild | Great-great-grandchild | 3x great-grandchild |
| Child | Parent | Sibling | Niece/nephew | Great-niece/nephew | Great-great-niece/nephew | 3x great-niece/nephew |
| Grandchild | Grandparent | Aunt/uncle | First cousin | First cousinonce removed | First cousintwice removed | First cousin3 times removed |
| Great-grandchild | Great-grandparent | Great-aunt/uncle | First cousinonce removed | Second cousin | Second cousinonce removed | Second cousintwice removed |
| Great-great-grandchild | Great-great-grandparent | Great-great-aunt/uncle | First cousintwice removed | Second cousinonce removed | Third cousin | Third cousinonce removed |
| 3x great-grandchild | 3x great-grandparent | 3x great-aunt/uncle | First cousin3 times removed | Second cousintwice removed | Third cousinonce removed | Fourth cousin |
Assumes full relatives. Half-relatives use the same names.
Quick Answers
| What is… | …to me? |
|---|---|
| My cousin’s child | First cousin once removed |
| My cousin’s grandchild | First cousin twice removed |
| My mother’s or father’s cousin | First cousin once removed |
| My mother’s cousin’s child | Second cousin |
| My father’s cousin’s grandchild | Second cousin once removed |
| My grandparent’s cousin | First cousin twice removed |
| My grandmother’s or grandfather’s sister | Great-aunt or great-uncle |
| My grandmother’s sister’s grandchild | Second cousin |
| My aunt’s or uncle’s grandchild | First cousin once removed |
| My sister’s or brother’s grandchild | Great-niece or great-nephew |
| My great-grandmother’s sister | Great-great-aunt or great-great-uncle |
How cousin names work
- Find the closest ancestor you both descend from. Siblings share parents, first cousins share grandparents, second cousins share great-grandparents.
- The number comes from the person closer to that ancestor. If one of you is a grandchild of the shared ancestor, you’re first cousins; a great-grandchild, second cousins; and so on.
- “Removed” is the generation gap. If the other person is one generation further down (or up), you’re once removed; two, twice removed.
- It works both ways. If they’re your first cousin once removed, you’re theirs too - the name doesn’t say who’s older.
The Whole Family, in One Private Album
Grandparents, aunts, the second cousins once removed - Clann keeps the family’s photos in one place, away from social media. It’s end-to-end encrypted: photos and videos are encrypted on your phone before they upload, and only your family’s own devices can open them. Grandparents can view through a simple web link, no app required.
Frequently Asked Questions
What is my cousin’s child to me?
Your first cousin once removed. They’re one generation below you, which is what “removed” means. Your own children and your cousin’s child are second cousins to each other.
What is my mom’s or dad’s cousin to me?
Your first cousin once removed - the same name as your cousin’s child, just one generation up instead of down. Their children are your second cousins.
What are my cousin’s kids to my kids?
Second cousins. Your children and your first cousin’s children share great-grandparents (your grandparents), and that is what makes two people second cousins.
What does “once removed” mean?
“Removed” counts the generations between two cousins. Once removed means one generation apart - your cousin’s child, or your parent’s cousin. Twice removed means two generations apart, like your cousin’s grandchild or your grandparent’s cousin. Cousins in the same generation aren’t removed at all.
What is the difference between a second cousin and a first cousin once removed?
A second cousin is in your generation and shares great-grandparents with you - your parent’s cousin’s child. A first cousin once removed is a generation away and shares your grandparents (or you share theirs) - your cousin’s child, or your parent’s cousin. People often call both “second cousin”, but only the first one is.
What do I call my grandparent’s brother or sister?
Great-uncle or great-aunt. Genealogists often prefer grand-uncle and grand-aunt, because they sit in the same generation as your grandparents. Both are correct. Their children are your first cousins once removed.
Are second cousins blood relatives?
Yes. Second cousins share a set of great-grandparents and, on average, about 3.13% of their DNA. Third cousins share great-great-grandparents and about 0.78%.
How much DNA do cousins share?
On average, first cousins share about 12.5% of their DNA, first cousins once removed about 6.25%, second cousins about 3.13% and third cousins about 0.78%. These are averages - real amounts vary, and from third cousins on some share no detectable DNA at all. Half-relatives (through only one shared grandparent) share about half as much.
Does this work for half-siblings and in-laws?
Half-relatives use the same names - your half-brother’s daughter is still your niece - they just share less DNA. In-laws aren’t blood relatives, so they have no place on the cousin chart: your cousin’s husband is usually just called your cousin-in-law.
Other tools: Baby Age Calculator, Baby Weight Percentile Calculator, Baby Height Percentile Calculator, Baby lb ⇄ kg Converter, Baby Sleep Calculator, Remove Location From a Photo.
Keep the Whole Family Close