Calculating Your Cousins


For cousins to exist, there must be a common set of ancestral parents, or even a single parent, of however many greats.  So, when a potential cousin asks you to figure out the relationship, determine who the common parental ancestors are, and their parental relationship to each of you, then...


1. If those parental ancestors are GRANDPARENTS to one or both of you, you are FIRST cousins.  FIRST cousins are the offspring of your aunts and uncles.
2. If they are GREAT GRANDPARENTS to one or both of you, then you are SECOND cousins.  SECOND cousins share your GREAT-GRANDPARENTS but not the same grandparents.
3. THIRD cousins share the same GREAT-GREAT-GRANDPARENTS.
4. FOURTH cousins share the same GREAT-GREAT-GREAT-GRANDPARENTS, and so on.

 Most computer genealogy programs will number your cousins (1st, 2nd, 3rd, etc.) and also tell you their degree of removal (once, twice, three times, etc.), but a simple chart will do the job equally well, and if you know TWO SIMPLE RULES you can even do it in your head.

SIMPLE RULE #1: Your cousin's position number may be determined by the least number of generations (greats) connecting either you or your cousin to the common ancestor(s).  Just count the G's.

I will use the chart below to find the relationship between myself and my relative Victoria Norris:
1. First I write down the descent lines from our common ancestor(s) for both Victoria and myself.  It will help to record the number of "Greats" beside each name:

(GGG) George Norris & Elizabeth Ridley --> (GG) John Norris --> (G) Martha Norris --> Blanche Russell --> ME
(G) George Norris  & Elizabeth Ridley --> George Norris --> Victoria Norris

2. I enter the name(s) of our common ancestor(s), George & Elizabeth, in the box at top left.
3. I enter family names, in generation order, showing my and Victoria's descents from George & Elizabeth. Enter one set across the top, the other set down the left side – as in the example.
4. The relationship between us is identified in the chart cell that is common to us both.  So Victoria Norris is my first cousin, twice removed.
Common Ancestor:
George Norris & Elizabeth Ridley		 Child
John Norris 		G-Child
Martha Norris		 GG-Child
Blanche Russell		 GGG-Child
Me		 GGGG-Child
Child
George Norris		 Brother / Sister Nephew / Niece G-Nephew / G-Niece GG-Nephew / GG-Niece GGG-Nephew / GGG-Niece
G-Child
Victoria Norris		 Uncle / Aunt 1st Cousin 1st Cousin 1x Removed **1st Cousin 2x Removed** 1st Cousin 3x Removed
GG-Child
s		 G-Uncle / G-Aunt 1st Cousin 1x Removed 2nd Cousin 2nd Cousin 1x Removed 2nd Cousin 2x Removed
GGG-Child
s		 GG-Uncle / GG-Aunt 1st Cousin 2x Removed 2nd Cousin 1x Removed 3rd Cousin 3rd Cousin 1x Removed
GGGG-Child
s		 GGG-Uncle / GGGAunt 1st Cousin 3x Removed 2nd Cousin 2x Removed 3rd Cousin 1x Removed 4th Cousin

Click here for a printable copy of the chart.


When the word "removed" is used to describe a connection, it indicates that the two people are from different generations. You and your first cousins are in the same generation (two generations younger than your grandparents), so the word "removed" is not required to describe your ancestral association.

"Once removed" means 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 closer to your grandparents than you are. This one-generation dissimilarity is reflected by "once removed."

Twice removed means that there is a two-generation disparity. You are two generations younger than a first cousin of your grandfather, so you and your grandfather's first cousin are first cousins, twice removed.

SIMPLE RULE #2: To get your cousin's removal number, subtract the lesser number of G's from the greater.  (i.e. if the common parental ancestors are GGG Grandparents to Person A, and G Grandparents to Person B, then subtract GG from GGGG and get "second cousin twice removed."


Oh yes, and in a case where only one of the common ancestral parents is shared (as in a remarriage with a second family) then you must place "half" in front of the relationship, as in "half first cousin once removed."
This chart may also help:




And this site from the BBC.