How to Calculate Degrees of Cousins

Understanding cousin degrees helps clarify family relationships. This guide explains how to calculate cousin degrees between two people and provides a calculator to determine the relationship.

What is a cousin degree?

A cousin degree refers to the number of generations between two cousins. It's determined by how many times you move up the family tree to find a common ancestor. The higher the degree, the more distant the cousins.

For example, first cousins share a common ancestor two generations back, while second cousins share a common ancestor three generations back.

How to calculate cousin degrees

Step-by-step method

Identify the two individuals whose relationship you want to determine.
Trace each person's lineage back to their common ancestor.
Count the number of generations between each person and their common ancestor.
Subtract one from the total number of generations to determine the cousin degree.

For example, if Person A is 3 generations removed from their common ancestor and Person B is 4 generations removed, the cousin degree would be (3 + 4) - 1 = 6, making them sixth cousins.

Formula

Cousin Degree = (Generations from Person A to Common Ancestor) + (Generations from Person B to Common Ancestor) - 1

Assumptions

Both individuals share at least one common ancestor.
The generations are counted from the individual to their common ancestor.
Half-cousins are considered first cousins.

Examples of cousin degrees

Here are some examples of cousin degrees between different family members:

Relationship	Cousin Degree	Description
Siblings	0	Share the same parents
First Cousins	1	Share one set of grandparents
Second Cousins	2	Share one set of great-grandparents
Third Cousins	3	Share one set of great-great-grandparents
Fourth Cousins	4	Share one set of great-great-great-grandparents

Frequently Asked Questions

What is the difference between first cousins and second cousins?

First cousins share one set of grandparents, while second cousins share one set of great-grandparents. The degree increases with each additional generation between the common ancestor and the cousins.

How do I calculate cousin degrees for half-cousins?

Half-cousins are considered first cousins because they share one set of grandparents, even though they have different parents.

Can cousin degrees be negative?

No, cousin degrees cannot be negative. The minimum degree is 0, which indicates siblings sharing the same parents.

How accurate is the cousin degree calculator?

The calculator provides an estimate based on the generations entered. For precise family relationships, it's best to consult a family tree or genealogy records.