How To Demystify Those Confusing Cousin Relationships

Discover and find your distant cousins with this guide to cousin relationships. Calculate cousin connections and connect with confidence.

As genealogists, we often focus on researching past generations without realizing how many living relatives might help us piece together our family story. 

In my personal research, I quickly discovered the value of oral history and interviewing my living relatives.  Every time I talked with a cousin or aunt I heard new names of more distant relatives. 

Sometimes I would just hear vague references to so and so’s son/daughter who might know something about the family history.

I knew I needed to find these cousins, understand our relationship AND talk to them!

This guide will help you understand cousin relationships and connect with extended family members who could enrich your research.

Understanding Confusing Cousin Relationships

Understanding cousin relationships makes most genealogists’ heads spin. First cousins are easy enough, but once you start adding “removed” or going to second and third cousins, things get complicated fast. Don’t worry – there’s a reliable way to figure it out.

The Basic Formula

To determine your relationship with a relative, follow these steps:

1. Find your common ancestors (usually the most recent shared grandparents)
2. Count the generations between you and those common ancestors
3. Count the generations between your relative and those same ancestors
4. Use these numbers to determine your relationship:
   • Subtract 1 from the smaller number to get the cousin degree (1st, 2nd, 3rd)
   • Subtract the two numbers from each other to get the “removed” count

For example:

• If you and your relative are both 2 generations from your common ancestors, you’re first cousins
• If you’re 2 generations away and they’re 3 generations away, you’re first cousins once removed
• If you’re both 3 generations away, you’re second cousins

Quick Reference:

• First Cousins: Share grandparents (2 generations to common ancestors)
• Second Cousins: Share great-grandparents (3 generations)
• Third Cousins: Share great-great-grandparents (4 generations)
• Fourth Cousins: Share great-great-great-grandparents (5 generations)

Using the Formula

When you meet a new relative, ask:

1. Who are our common ancestors?
2. How many generations am I from them?
3. How many generations is my relative from them?

For instance:

• Your grandparents are 2 generations from you
• Your great-grandparents are 3 generations from you
• Your great-great-grandparents are 4 generations from you

This method works for any cousin relationship, no matter how distant or complex.

Need to see it in chart from? Take a peek at this chart over at Legacy Tree Genealogists.

Types of Cousin Relationships

Let’s break down each cousin type and what it means in practical terms. Think of each generation as a step away from your common ancestors.

First Cousins

You and your first cousins share grandparents. This means:

• You are the children of siblings
• You are two generations away from your common ancestors (your grandparents)
• Example: Your mom’s sister’s kids are your first cousins

Second Cousins

You and your second cousins share great-grandparents. This means:

• You are the children of first cousins
• You are three generations away from your common ancestors (your great-grandparents)
• Example: Your mom’s cousin’s kids are your second cousins

Third Cousins

You and your third cousins share great-great-grandparents. This means:

• You are the children of second cousins
• You are four generations away from your common ancestors (your great-great-grandparents)
• Example: Your mom’s second cousin’s kids are your third cousins

“Once Removed” Explained

When we say a cousin is “once removed,” we’re talking about relatives who are one generation apart. This can happen in two ways:

• Going down a generation: Your first cousin’s children are your first cousins once removed
• Going up a generation: Your parent’s first cousins are also your first cousins once removed

“Twice Removed” Explained

“Twice removed” means there are two generations between you and your cousin:

• Going down two generations: Your first cousin’s grandchildren are your first cousins twice removed
• Going up two generations: Your grandparent’s first cousins are also your first cousins twice removed

Simple Rule of Thumb

• To find the cousin type (first, second, third): Count the generations to your common ancestors and subtract 1
• To find how many times removed: Count the generation difference between you and your cousin

This systematic approach helps you determine any cousin relationship you encounter in your family tree.

Special Cousin Types

Beyond standard cousin relationships, there are several special types of cousin relationships that occur in families. Understanding these can help you make sense of more complex family connections.

Half-Cousins

Half-cousins share only one grandparent instead of two. This happens when:

• Your parent and their cousin-parent are half-siblings (sharing one parent)
• Your grandparent remarried and had more children
• One of your grandparents had children with multiple partners

For example:

• If your father’s half-sister has children, they would be your half-cousins
• You share one grandparent (your father’s parent) but not both grandparents

Double Cousins

Double cousins occur when two siblings from one family marry two siblings from another family. This creates a unique situation where:

• The children share both sets of grandparents
• They are cousins through both their mothers and their fathers
• Genetically, they share about twice as much DNA as typical first cousins

Why These Distinctions Matter

Understanding these special cousin types is important because:

When documenting family history, note these special relationships to maintain accuracy in your family tree and help future generations understand their family connections.

• It helps explain family DNA test results
• It clarifies inheritance and medical history patterns
• It helps you understand family dynamics and relationships
• It’s useful for accurate genealogical research

Finding & Connecting With Those Distant Cousins

We want to talk with these second, third and fourth cousins, right? So how do we find them, and how do we connect with them?

Will they think I am a nutcase if I contact them?  Will they hang up on me?

Should we even try?  YES!

How do you find “new cousins” to interview?

• Interview the family members you do know.  Rarely will you leave one oral history interview without the names of other relatives being suggested.
• Contact other researchers who are researching the same or similar family lines. They often have suggestions.
• Contact the local genealogy and/or historical society for the area you are researching.  Many of these members are longtime residents and have a vast knowledge of the people and area.

Once you have identified a distant relative you wish to interview:

How do you contact that person you do not know for information?

• If possible, have a mutual acquaintance introduce you.  This can be done in person or by phone. This is the easiest and quickest way.  It’s just not always possible. If not……
• Send a brief note by snail mail to introduce yourself.  Reference where you fit in the family tree. Provide enough context of your relationship in the family, but do not overwhelm them by giving them the whole tree!  For example, “I am Winnie Haley Carr’s great-granddaughter. My grandmother was her daughter Anita.”   If you have a blog or website, include that as well. Lastly state you will follow up with a phone call in a few days. (Make sure you do!) Remember your goal is to make this person feel comfortable enough to talk to you.

I have had great success contacting distant relatives using these methods.  Obviously, I am most nervous using the second method. I still get nervous reaching out like this, but I’m more than willing to get outside of my comfort zone to find those ancestors.

Let me share an example of one of my successes.

I wanted to talk with a cousin on a different Howard family line than I had descended.  She lived about 45 minutes away. I sent her a snail mail note as described above.  I included my card and stated where I fit in the Howard family line. I then called her a few days after I knew she would have received my note.  Her first words?  “I’ve been waiting for your call!” 

Stepping out of my comfort zone and past my nervousness yielded invaluable information to my research.

Your challenge?  

Contact that distant cousin, aunt, or uncle and ask them your questions. Be sure and let me know in the comments below how it went.)

You will both be richer in family history for it.

Learn more in these posts:

• Use Social History in Genealogy Research – Telling Your Ancestors’ Stories
• Why Your Ancestor’s Occupation Matters To Your Genealogy Research
• 3 Great Benefits of Crowdsourcing Family Stories From Old Photos