Cousins Chart: Understanding Your Family Relationships

Having trouble coming up with the proper term for your mother's uncle's father for your family tree? Here's a guide to who's who in the family structure.

Second cousin twice removed. Sounds mathematical, as though establishing a family relationship required the use of trigonometric algorithms. But like so many apparently daunting areas of expertise, it's really just a matter of learning the lingo. In the definitions below, "you" serve as the frame of reference, around which all the other relations revolve.

Uncle and Aunt

Your parents' brothers and sisters, and their spouses. You don't need any blood connection to be a full-fledged aunt or uncle. Your mother's sister's husband is not your uncle by marriage. He's your uncle, fair and square.

Niece and Nephew

Son and daughter of your siblings and siblings-in-law. As with uncle and aunt, they're not your nieces and nephews by marriage, they're your nieces and nephews, plain and simple, even if they're your spouse's siblings' kids and don't have a single drop of blood in common with you.

First Cousin, Full Cousin, Cousin-German

Children of your parents' brothers and sisters. You and your first cousins share one set of grandparents.

Double First Cousins

If a pair of brothers marries a pair of sisters, their kids are not only first cousins, they're double first cousins: They have both sets of grandparents in common.

Second Cousins

You and the children of your parents' cousins are second cousins and share at least one great-grandparent. Your child and your cousin's child are second cousins.

Third Cousins

You and the children of your parents' second cousins are third cousins and share at least one great-great-grandparent. And so on with the fourth, fifth, and sixth cousins.

First Cousin Once Removed

A relationship that is removed is one that exists in two different genealogical generations. Generation refers to the order of birth, a genealogical level. Your aunt and your mother may have been born 20 years apart, but they are still of the same generation. Your parent's first cousin is your first cousin once removed. The child of your first cousin is also your first cousin once removed: your grandparent is that child's great-grandparent. You can do the whole "removed" thing for every category of cousins—second cousin once removed, and so on. But by then you'll probably drive everyone completely crazy.

Grandaunt and Granduncle

We always called grandpa's sister "great-aunt." But the experts say that terminology is incorrect, and the terms above should be used instead to refer to the siblings of your grandparents. (Which doesn't mean we have any intention of using them.)

Great-Grandaunts and Great-Granduncles

Your great-grandparents' brothers and sisters.


Family by marriage: Your spouse's parents, spouses of your siblings, and spouses of your spouse's siblings. That is, your brother's wife is an in-law, but none of her siblings are. And your husband's sister's husband is your in-law, but none of his brothers are. And in-laws pretty much stop with your parents-in-law and your siblings-in-law. You are not in-laws with the parents of your sister-in-law's husband. And the two sets of parents of a couple are not in-laws to each other either; they are the competitive parents—an entirely different category.

Affinity Relatives

Your husband or wife's blood relatives -- the in-laws that are biologically related to your spouse.

Birth Mother, Biological Mother, Natural Mother

Terms for the biological mother of a child who has (usually) been adopted by other parents.

Adoptive Mother

Mother of a child who is not biologically her own.


  1. My aunt becomes a widow and remarries and she has children from this second marriage. Are these children my first or second cousins? Thank you

  2. How is my granfather's great-great uncle related to my grandmothers sisters grandchildren. I say they are not...only my grandma will hold a title since she married into the family, but my cousin says that all of my grandma's family will be family to my grandfathers great-great-uncle. Can someone explain this to both of us, please and thank you!

  3. Help! My boyfriend’s great aunt is married to my great uncle. Are we related? In longer terms, my boyfriends grandma’s sister is married to my grandfather’s brother.

    1. You two are in no way blood related. Trust me I just sat down and drew out a family tree to be certain so you have nothing to worry about. Two people from separate families got married. Those people didn't produce children that then produced yourselves. There is a title for your "family relationship" but it is no way crossing any boundaries or lines at all. You are not even slightly blood related at all based off the information you have provided.

    2. Kind of, the way I was told by a professor to look at it is, Non-Biological third cousins

  4. If my grandfather's cousin has kids and then my grandfather's cousins daughter has children then what would that make me to those children?

  5. Hey, how do you call your mother's cousin (same great-grandparents) and is it okay to have a crush on them?

  6. I don’t know if this is the right place for this type of question but I don’t know who else to ask. I’ve know for years but until recently I’ve been confirmed that my parents were cousins and I really want to know if that could in any way affect my future children? And No, my partner wouldn’t be related to me. (Could you reply to this at my email? for easier communication? Please and thank you!)

    1. Genetically speaking... you would have been affected if it would have happened. If you werent ‘green’ you’re likely okay.

      Don’t have kids in the family, and they should be okay.

      Btw 3 led cousins is generally considered ok. Genetically speaking. Look at Britain ;)

  7. I have a sister who is married to her third husband with kids by each husband. The kids are all married and have kids that are dating offspring from her other marriages. All of the dads are remarried. What will that make the kids own kids if they should have them to their first cousins?

    1. First of all your sisters ex-husbands (the dads) that are remarried is a moot point. Meaning it doesn’t matter and has nothing to do with this. If your sisters kids (they are all half siblings) and they are all married with kids, those kids are dating one of her kids from a previous marriage? That would make them dating their half aunt/uncle. They still share quite a bit of dna. That’s gross and illegal! Ur family needs Jesus. I rlly hope u r trolling!

    2. Do you live in WV, LA, AL, UT? You’d probably call them cousins of the shallow gene pool. They could be easy to ID at family gatherings by the number of teeth they have, whether they have congenital heart or other genetic mishaps. In most states, I suspect their marriage to one another would be illegal in order to protect their offspring from congenital defects. Poor kids.

  8. If my cousin has a kid, what would that kid be to me

    1. First cousin once removed. I thought most of my life that it would be a second cousin. But, I have been proved incorrect:(

  9. What would my great grandma’s first cousin’s kid be to me?

  10. Say you have a friend. He tells you that he has a cousin on his dad’s side that’s YOUR cousin on your mom’s side. (It’s very awkward rn) What does that make me and my friend???

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