Family Relationship Chart

Common Ancestor =========

======== Child ========

==== Grandchild ====

Great Grandchild ========

Great Great Grandchild ========

Great Great Great Grandchild

======== Child ========

======== sister or brother

======== Nephew or Niece

======== Grand-nephew or niece

Great Grand-nephew or niece

Great Great Grand-nephew or niece

==== Grandchild ====

======== Nephew or Niece

======== First cousin ========

======== First cousin, once removed

======== First cousin, twice removed

First cousin, three times removed

======== Great Grandchild

======== Grand-nephew or niece

======== First cousin, once removed

======== Second cousin ========

Second cousin, once removed

Second cousin, twice removed

======== Great Great Grandchild

Great Grand-nephew or niece

======== First cousin, twice removed

Second cousin, once removed

======== Third Cousin ========

======== Third cousin, once removed

Great Great Great Grandchild

Great Great Grand-nephew or niece

First cousin, three times removed

Second cousin, twice removed

======== Third cousin, once removed

======== Fourth Cousin ========

click here to open a chart in its own page

To find out the relationship between you and another relative first go to the common ancestor box and plug in your closest generation grandparent that you and that relative have in common. For instance Grampa Harry may be your grandfather, but a relative's great grandfather. If this is the case, than that relative is your first cousin once removed.

Try it with all your relatives, even those you know the relationship between (except your own parents or siblings)
I'll start. My Aunt Helen is my dad's sister. I can plug in my grandmother (Yia Yia) in the common ancestor box.. I move down the left column to find me (grandchild). I move across the top to find Aunt Helen's relationship to my grandmother, which is child. Moving down and across from the two spots they meet at the box nephew or niece. So I am Aunt Helen's niece.

So if my cousin Vinny is my first cousin and he has a grandchild how am I related to his grandchild?
His grandchild and I have my grandparents as a common ancestor. So down the left column I stop at grandchild for me. Across the top I need to go all the way to great great grandchild. So cousin Vinny's grandchild is my first cousin twice removed.

............A
........../.. \
........./.... \
.......B .....C
......./ .........\
....../ ...........\
....D ............E
..../................ \
.../.................. \
F..................... G

So A is B&C's parent
A is D&E's grandparent
A is F&G's great grandparent
To find the relationship between B&G simply go to the chart. B is a child to A. So find child across the top. G is a great grandchild to A, so find great grandchild down the side. Therefore G is a Grand-nephew or niece to B.

Double first cousins- When two siblings marry two other sibling. (so if Bob and Joe are brothers and they marry sisters Jane and Josie. Or Mike and Jill who are brother and sister marry Faith and Jack who are also brother and sister). The children of these couples are related to each other through both parents' families. Double first cousins have both sets of grandparents in common. Genetically, they are as related as half-siblings.

"identical" twins If identical twins marry another set of siblings the kids of the couples are more related than half-siblings but less related than full siblings (they are genetically equivalent to 3/4 siblings) although they are legally double first cousins. If identical twins marry another set of identical twins (sometimes called "quaternary marriage"), genetically they are like full siblings. They are classified as double first cousins.

There are even other types of cousins.
Click Here to Check it out