# What Is a Second Cousin? Calculate Your Cousin Relationships

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Trying to figure out what to call your family relationships? What is a second cousin? A third cousin? Letâ€™s answer the questions weâ€™ve all asked ourselves about our family treeâ€”and see a handy chart that explains how we calculate cousinhood.

When it comes to cousins, the relationship possibilities are endless. Your number of grandparents doubles with each generation. Count back 10 generations, and thatâ€™s 2,046 total ancestors, which means the potential cousin population is exponential. You could have millions of them: fourth cousins, second cousins three times removed, tenth cousins twice removedâ€”we could go on.

With DNA testing, Facebook, online family trees, and message boards that can connect you to new cousins every day, youâ€™re bound to become curious about precisely how youâ€™re related.

Hereâ€™s how to determine the kind of cousins you are based on degrees of separation from shared ancestors.

### What Makes Someone a Cousin?

Answer: The fact that you share an ancestor with that person. To understand cousin relationships, remember that your ancestors are only the people in your direct line: parents, grandparents, great-grandparents, and so on. Your ancestorsâ€™ siblings are aunts and uncles (no matter how many â€śgreatsâ€ť you count)â€”not ancestors.

Just about any other blood relative who is not your sibling, ancestor, aunt, or uncle is your cousin. To determine your degree of cousinhoodâ€”first, second, third, etc.â€”you need to identify the ancestor you share with your cousin and how many generations separate each of you from that ancestor.

### What is a First Cousin

Your first cousin (aka full cousin) is the child of your aunt or uncle. The most recent ancestor you and your first cousin share is your grandparent. You typically share 12.5 percent of your first cousinâ€™s DNA.

### What is a Second Cousin

Your second cousins are the children of your parentsâ€™ first cousins. You and your second cousins have the same great-grandparents! You typically share 3.125 percent of your second cousinâ€™s DNA

### What is a Third Cousin

Third cousinsâ€™ most recent common ancestors are great-great-grandparents. Thereâ€™s a 90% chance third cousins share DNA. That said, third cousins who share DNA only typically share .781% of their DNA with each other.

### What Is a â€śRemovedâ€ť Cousin?

A â€śremoveâ€ť happens when two cousins have different numbers of generations back to their most recent common ancestor. One generation of difference equals one remove.

To calculate this, count the number of generations from each cousin back to the common ancestor. The cousin with the lower number of generations determines the degree of cousinhoodâ€”first, second, third, and so on. Subtract the lower number of generations from the higher number to find out how many times removed the cousins are.

### Double Cousins

This is a special cousin category for the offspring of brothers- and sisters-in-law. For example: Your sister weds your husbandâ€™s brother. Instead of sharing one set of grandparents, as first cousins do, double cousins share both sets of grandparents. As you might expect, double cousins have more DNA in common than typical first cousinsâ€”about 25 percent.

### Kissing Cousins

A kissing cousin is not a cousin you marry. Instead, itâ€™s any distant relative whom you know well enough to give a â€śhelloâ€ť kiss to at family gatherings.

This begs the question: How close a cousin is too close to wed? States have different laws governing consanguineous marriages. Itâ€™s best to ask a lawyer about statutes for the state in question.

### Whoâ€™s Not a Cousin?

Due to limited mobility in our ancestorsâ€™ day, most of us have instances in our family trees of cousins who married, knowingly or unknowingly. This means that you can be related to the same person in multiple ways.

Someone youâ€™re related to by marriage, rather than by blood, is not your cousin. You might be in-laws, or your relationship might be â€śgood friends.â€ť

You can learn more about collateral degree calculation (aka family relationships) in Lois Horowitzâ€™s Dozens of Cousins (Ten Speed Press, 2004) or Jackie Smith Arnoldâ€™s Kinship: Itâ€™s All Relative (Genealogical Publishing Co., 2009).

Speaking of family, letâ€™s talk about family names! See our article about baby names trends and the baby-naming game!