Cousins Explained
Have you ever got your first cousins twice removed confused with your second cousins once removed? Well, you're not the only one. This chart attempts to explain the relationships that exist between cousins. It may be extended in either direction for as many generations as is necessary.
| Parents | Child | G-Child | GG-Child | GGG-Child | GGGG-Child |
| Child | Brother/Sister | Nephew/Niece | G-Nephew/G-Niece | GG-Nephew/GG-Niece | GGG-Nephew/GGG-Niece |
| G-Child | Uncle/Aunt | First Cousin | First Cousin once removed | First Cousin twice removed | First Cousin thrice removed |
| GG-Child | G-Uncle/G-Aunt | First Cousin once removed | Second Cousin | Second Cousin once removed | Second Cousin twice removed |
| GGG-Child | GG-Uncle/GG-Aunt | First Cousin twice removed | Second Cousin once removed | Third Cousin | Third Cousin once removed |
| GGGG-Child | GGG-Uncle/GGG-Aunt | First Cousin thrice removed | Second Cousin twice removed | Third Cousin once removed | Fourth Cousin |
The parents represent the common ancestors you have with your relative. Count across the top row until you reach your generation. Now count down this column until you reach your relative's generation. This gives you your relationship to your relative. If you have only one common ancestor with your relative (perhaps this ancestor had multiple marriages), then the same chart applies but the relationships are half blood instead of full blood. In general, the person in the first row is the ***** of the person in the first column where ***** stands for the appropriate table entry, eg. sister, uncle, second cousin, etc.
Example - Suppose I want to find out my relationship to the son of my grandmother's brother. Then the common ancestors that we share are my great-grandparents which are his grandparents. (I am assuming a full blood relationship). Therefore, reading from the chart we find that
| Parents | Child | G-Child | Me |
| Child | Brother/Sister | Nephew/Niece | G-Nephew/G-Niece |
| Relative | Uncle/Aunt | First Cousin | First Cousin once removed |
I am the first cousin once removed of this relative.
You can also use the calculator here to ascertain the relationship between cousins. You may need to enable Active X controls to properly view the page.
Cousin Terms and Definitions
Cousin (or First Cousin or Full Cousin)
The son or daughter of an uncle or aunt.
Second Cousin
People who have the same great-grandparents, but not the same grandparents.
Third, Fourth, and Fifth Cousins
Third cousins have the same great-great-grandparents, but not the same great-grandparents or grandparents. Fourth cousins have the same great-great-great-grandparents, etc.
Removed
When the word "removed" is used to describe a relationship, it indicates that the two people are from different generations. The words "once removed" mean that there is a difference of one generation. For example, your father's first cousin is your first cousin, once removed. This is because your father's first cousin is one generation younger than your grandparents and you are two generations younger than your grandparents. This one-generation difference equals "once removed." The one-generation difference has nothing to do with age, but rather with descendance from the same person.
Twice removed means that there is a two-generation difference. You are two generations younger than a first cousin of your grandmother, so you and your grandmother's first cousin are first cousins, twice removed.Half Cousin
First cousins are the children of siblings; therefore, half first cousins would be the children of half siblings. Half-cousins would have one common grandparent instead of two common grandparents.
Cross Cousin
A cousin who is the child of one's mother's brother or one's father's sister.
Parallel Cousin
A cousin who is the child of one's mother's sister or one's father's brother. Parallel cousins are the children of two brothers or two sisters.
Double Cousins
If two siblings in one family marry two siblings from another, and each couple has a child, these children are double cousins. The addition of the word double to the first cousin term is the result of the number of common grandparents they have. Regular first cousins share only one set of common ancestors, while double first cousins share all lineal and collateral relatives.
