Relationship Finder

What is my grandpa's brother's grandson to me?

Your grandpa's brother's grandson is your second cousin, and you are his second cousin too.

3.13% shared DNA on average. Real amounts vary.

Diagram: how your grandfather's brother's grandson is related to youYouParentGrandfatherGreat-grandparentscommon ancestorsGreat-uncleFirst cousin onceremovedSecond cousinthem

you them common ancestors double line: marriage

Your grandpa's brother is your great-uncle. His grandchildren are in your generation, and you all descend from the same couple: your great-grandparents. Same generation + shared great-grandparents = second cousin.

His children (your great-uncle's sons and daughters) are one generation up. They are your first cousins once removed, and your parent's first cousins.

How we worked it out

Follow the chain one step at a time:

  1. Your grandfather: grandfather (2 up, 0 down)
  2. Your grandfather's brother: great-uncle (3 up, 1 down)
  3. Your grandfather's brother's grandson: second cousin (3 up, 3 down)

Your great-grandparents are his great-grandparents: they are your common ancestors.

Same generation as you.

Count the generations to your common ancestors: 3 up from you, 3 down to him. The cousin number is one less than the smaller count (3), so second cousin. The counts are the same, so not removed.

Check another relative

My
    …

    Tap relatives in order, like mother, cousin, daughter
    More: grandchildren, great-, half-, step- and in-laws
    Any sex Grandchildren and great- Half Step In-laws

    Related questions

    What is my grandpa's brother's son to me?
    Your first cousin once removed (your parent's first cousin).
    What is my great-uncle's granddaughter to me?
    Your second cousin, the same as his grandson.

    More family relationship answers