A CHART OF CONSANGUINITY

"Kinship Chart"
Helps to identify the relationship of those sharing common ancestors.

O P GP GGP 3GP 4GP 5GP
P S N GN 2GN 3GN 4GN
GP N 1C 1C
1R
1C
2R
1C
3R
1C
4R
GGP GN 1C
1R
2C 2C
1R
2C
2R
2C
3R
3GP 2GN 1C
2R
2C
1R
3C 3C
1R
3C
2R
4GP 3GN 1C
3R
2C
2R
3C
1R
4C 4C
1R
5GP 4GN 1C
4R
2C
3R
3C
2R
4C
1R
5C
 C = Cousin P = Parents G = Great/Grand N = Nephew/Niece O = Original Ancestors R = Removed S = Sibling (brother or sister) Examples: 1C = First Cousin GGP = Great Grand Parents 2C1R = Second Cousin, Once Removed GN = Grand Nephew/Niece 3GP = Great Great Grand Parents 5GP = Great Great Great Great Grand Parents

Locate one person along the top row, according to his relationship to the Original Ancestors (O). Locate the other person along the left hand column, according to his relationship to the same Original Ancestors and where the two lines cross indicates the relationship of the two people to each other. If needed, the pattern can easily be extended.
If you and I have the same Parents (P), then we are Siblings (S).

If my Grandparents (GP) are also your Grandparents (GP), then you and I are first cousins (1C).

My Great Grand Mother's brother is my Great Grand Uncle, so I'm his GGN, because our Original Ancestors are their Parents (P), and are also my Great Great Grand Parents (GGGP).

In reverse, if someone is your third cousin (3C), it means that you both share the same great-great-grandparents (3GP).

Be sure to use the nearest Original Ancestors that you share or you can come up with such ridiculous things as:
Since my Grandparents are my son's Great-Grandparents, therefore my Son is my first cousin, once removed (1C1R). Whoa...!
Kith and Kin
HALF -"Half" means you share only one parent. Example: half-brothers may have the same father but different mothers, etc.

STEP - Not blood kin, but a close legal relationship due to re-marriage of a parent, such as step-mother, step-brother, step-son, etc.

DOUBLE FIRST COUSINS - Are first cousins twice, once on their Father's side and once on their Mother's side, since their Father's sibling married their Mother's sibling.

IN-LAW - They are not really blood kin but are treated as such because they married blood kin.
Example: Your Mother-in-law is not really your Mother but is treated as such because you married her daughter/son.