What is a First Cousin Once Removed? | Cousin Once Removed Meaning

Diahan Southard

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What is a first cousin once removed, and so forth? We are here to help you understand the cousin once removed meaning. Removed cousins on your family tree likely account for a TON of DNA matches. This article has a diagram showing different ways you might be a cousin once removed!

first cousin once removed 1st cousin once removed cousin 1C1R DNA family tree IO.pngWhen you see a DNA match list on your DNA testing site, you also generally see a few suggestions about how you might be related: “1st-2nd cousin,” for example. This might seem easy, at first glance. You likely know what a first cousin is: you share a set of grandparents (one of your parents is a sibling of one of your cousin’s parents). You may even know that a second cousin means you share a set of great-grandparents (one of your grandparents is a sibling of a second cousin’s grandparent).

But what’s NOT always so clear is that you have other possible relationships, too. Here’s an example: if I click on the shared DNA details for one of my 1st-2nd cousin matches at AncestryDNA, I see the chart below. Woah! They’re giving me WAY more possibilities than a first or second cousin! In fact, the option for a 1st cousin once removed shares the top of the list!

what is a removed cousin DNA matches.png

What you’re seeing are all the genealogical relationships that lie within the range of possibilities for the amount of DNA you share with this match. Family trees can be complicated things, with half-relationships (one shared parent) and removed relationships. In this quick article, we’re focusing on the meaning of cousin once removed relationships.

What does first cousin once removed mean?

A removed cousin is someone who is on a different generation from you. So people who are one generation younger would be on the same generation as your children. People who are one generation older would be on the same generation as your parents.

There are two ways you can be first cousins once removed (1C1R); both are illustrated below. We will start with the easier situation, where your first cousin once removed is younger than you are. That means they are on the same generation as your children. Now, think of your first cousin. Do you have them in mind? Ok, now think of one of their children. That person is YOUR first cousin once removed. That was the easy one.

Removeds.png

Now to tackle the situation where your 1C1R is older than you. I want you to think of your dad’s first cousin. So those are the children of your dad’s aunts or uncles. Do you have one in mind? Do you see how you are THEIR first cousin once removed? You are that child of THEIR first cousin.

Why does this matter? It matters because knowing if a match is removed from you helps you to better understand how far back in their family tree you will need to go before you should run into the ancestor(s) you have in common. Very generally speaking, if they are a removed cousin who is younger than you, you will need to look further back in their family tree before you can expect to find your common ancestor. Of course, the opposite is true for a cousin who is once removed but older. You should be able to look in their tree at a more recent generation to find your common ancestor.

First cousin once removed? Half cousin? Something else?

One way to figure out how you’re related to your DNA matches is to ask them. Between the two of you–what you each know about your family tree–you might be able to figure it out. But starting (and keeping up) a conversation with a DNA match can be tricky. That’s why we wrote a guide to contacting your DNA matches. Would you like a free copy? We thought you might.

Get My Free Guide to Contacting DNA Matches

Haven’t taken a DNA test yet?

It’s a great way to find cousins (removed or not). DNA is a fascinating way to look at your unique origins. But you may have some questions or concerns about how the whole thing works. That’s why we wrote a free guide: What You Need to Know about DNA Testing for Family History. Would you like a free copy? It’s yours for the asking.

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<a href="https://www.yourdnaguide.com/author/guideyourdnaguide-com" target="_self">Diahan Southard</a>

Diahan Southard

As founder and CEO of Your DNA Guide, Diahan Southard has been teaching people how to find family history answers in their DNA for several years, and she's been in the genetic genealogy field since its infancy. Diahan teaches internationally, writes for popular magazines, consults with leading testing companies, is author of Your DNA Guide–The Book, and producer of Your DNA Guide–the Academy, an online learning experience.

60 Comments

  1. Kay Gregory-Clark

    Diahan, this is the first cousins chart I’ve seen that is truly helpful. I’ve pretty much ignored my test results for months because it was all too complicated. I listened to your podcast "Organizing…." and have ordered the book. With your help, I’m finally beginning to understand DNA. Thank you so much!

    Reply
    • Diahan

      I am so glad to hear that! I can’t wait to hear what you think of the book!

      Reply
    • AJ

      My dad was the oldest his mother’s sister had one kid named Nick so that was Dad first cousin correct the next fast my dad is fast and I have four brothers and one sister so these lawyers sent me a package and said I am the first cousin wants to remove is this true and I am in the driver’s seat of his estate and all these other cousins are contesting it or they’re fighting it’s crazy it’s out of this world he had a lot of money

      Reply
    • Daryl Stewart

      My son recently received his DNA results back. His Aunts Daughter (Mother’s Sister) is listed as First Cousin once removed. He is three years older. Please explain. (Confused)

      Reply
      • Your DNA Guide

        The relationships listed next to DNA matches on testing sites is just the company’s best guess based on the amount of DNA the two people share. Like anytime we make a guess, sometimes the relationships they suggest are correct, sometimes they’re not. The amount of DNA that first cousins share is 400-1400 cM, whereas first counsins once removed share 100-1000 cM. You can see from those two ranges that there is a lot of overlap, so if, for example, your son and his cousin are sharing 600 cM, it would be difficult to tell from just amount of shared DNA what their exact relationship is. This article explains it even more: https://www.yourdnaguide.com/scp

        Reply
      • Maryanne

        How do you remove names to do research .

        Reply
      • Andrea Wales

        The author was actually giving two specific situations, and they don’t apply to everyone, especially if the person comes from a big family in which the difference in ages between the oldest child and the youngest child spans a long time. It’s really not about who’s younger or older; it’s about the generation that the person falls under.

        Reply
  2. Billy Steele

    I am trying to find my biological father, I found several 1st cousins removed,

    Reply
    • Diahan Southard

      Billy, if those first cousins once removed are younger than you are, then one of their 4 great grandfathers is your grandfather.
      So you need to find out more about them, so you can find out more about you.

      Reply
      • AnnMarie Corbett

        I am interested in finding my Biological Father and his family.
        I do not know his name or anything about him only that my mother was impregnated by him. All I know he was military.

        I know everyone on my mother’s side, her parents and ( my grandparents and their parents).

        Reply
        • Sunny Morton

          AnnMarie, Looking for a birth father isn’t always easy. It will help that you know your mother’s side, because once you take a DNA test, you can more easily identify your DNA matches who come from her side and set them aside while you focus on matches who are related to your biological father.

          This article will get you started: https://www.yourdnaguide.com/ydgblog/how-to-find-birth-father-without-his-name.

          We also suggest downloading our free guide to getting started with birth roots: https://www.yourdnaguide.com/dna-birth-family.

          We encourage you to keep in touch with us during your birth roots journey; our mission is to help people use DNA to explore their important questions. Sign up for our free newsletter for a dose of monthly encouragement and DNA tips: https://www.yourdnaguide.com/newsletter

          Reply
          • Leon

            I grew up not knowing my parents, and I do not want to know them at this point. I am educated, married +40 years, and retired. I’m living a wonderful life. If anything their absence gave me more opportunities, loving people, and taught me self motivation and work for my goals. Now, I have some people attempting to track me down and reach out to me by email as “lost relatives”. They are using DNA and Family Trees to do so. How do I defend myself or tell they to leave me alone (for life). I am afraid they will just keep fading in and out of my life as they have done for 2 years due to DNA. Each of these people harass me with request for correspondence, meetings, and visiting. Please, help me out of this DNA Hell.

  3. June

    Hello I am trying to find out what happened to my fathers real mother . She left my grandfather when my father was a child , leaving her children. I think she had no choice in the matter. Someone has come up on DNA a match that is a first cousin once removed . If my grandmother went on to have more children could this person be another grandchild , my cousin once removed , but by another man not related to me ?

    Reply
    • Diahan Southard

      Hi June. You are thinking about this the right way in that you are trying to figure out what the relationship of a descendant of your missing grandmother would look like genetically. So if your grandma had other children, they would be your father’s half siblings. Her grandchildren would be your half first cousins. Her great grandchildren would be your half first cousins once removed. So check those relationships against the total amount of shared DNA and see what you come up with.

      Reply
      • Alee

        What about 2nd half cousin once removed? I can’t quite wrap my head around it.

        Reply
        • Diahan Southard

          A half-second cousin once removed would be someone who shares one great-grandparent with you, and is one generation lower than you (ie one of your great grandparents is their 2x greats). Alternately, a half second cousin once removed would be someone who one of their great grandparents is one of your 2x greats.

          Reply
  4. Ronald McAvoy

    I have a 3rd. great grandmother on my mother’s side that I know her first name and when she was born and died and born in Pa. What I don’t know is her Madian name. Is there a way to use my DNA to lead to her name? I’ve done 23 and me and Ancestry both.
    Ron McAvoy rmcavoy414@aol.com

    Reply
    • Diahan Southard

      This will be tricky as you are actually looking for a 4X great grandparent. I usually draw the line with Autosomal DNA testing (the kind you had tested) at the 3X great grandparent level.
      So what DNA testing may be able to do is find you other people who are descendants of your 3X great grandmother that you may not have connected with before. Sometimes by doing that, you can find records for those other descendants that might help you.

      Reply
  5. Kerstin

    Hi I am trying to find my husband biological father. He matched with a women 89% once removed We believe her first cousin is my husband father is that right ??? Also the lady’s father has 9 siblings .He has brothers and sisters so is it more on the boys side He is related or the girls side

    Reply
    • Diahan Southard

      Hi Kirsten if you husband and his match are first cousins once removed, and your husband is older, then the match’s great grandparents are your husband’s grandparents. This would be a really good thing to go over in a mentoring session, so I can look at the data and make some recommendations. http://www.yourDNAguide.com/thementor.

      Reply
  6. Kerstin

    Hi I am trying to find my husband biological father. He matched with a women 89% once removed We believe her first cousin is my husband father is that right ??? Also the lady’s father has 9 siblings .He has brothers and sisters so is it more on the boys side He is related or the girls side He also matches with the lady daughter 53% 2nd cousins first cousin 2 twice removed
    But matches with the other daughter higher l more 68%
    Thank you for your help

    Reply
  7. Amanda

    Hello I am trying to find my biological father. Ive submitted DNA on ancestry and 23 and me. I have found a half brother I am incontact with. Our next closest match is a male first cousin once removed at 686 cm. He is older. I’ve bought your book and I’m trying to go through the different charts you have but I’m having trouble.

    Reply
    • Diahan Southard

      Hi Amanda. So your half brother doesn’t know who his father is either?
      As 686 cM match, what makes you think you are 1C1R? If he is, then his grandparents are your great grandparents.
      But at 686 he could also be a half uncle. So a half brother to your father.

      Reply
      • Mary MacRae

        I have worked with you regarding DNA matches and my 3x grandfather. I am looking for his parents. Downstream from him, I know my matches. Upstream the matches are distant, 5th-8th cousins. A recent match showed up, 4th -6th cousin (24 CMs).he is my daughter’s age so assuming 1 gen removed. All common matches are my downstream (3x ggfather) cousins. Is it reasonable to conclude he descends from the same couple as I do, perhaps parents of my 3x grandfather? Been waiting for this match for along time, I am afraid that I am drawing the wrong conclusion. Thanks!

        Reply
        • Diahan Southard

          Based on the common matches you have evaluated, it is reasonable to assume this new match descends from the same family as you and those downstream cousins. But you share several ancestors with those downstream cousins!

          Your common ancestor to this new match could actually be your 3x ggfather, or his parents (your 4x ggparents) or even your 3x ggmother (unless you have ruled her/her family out another way).

          For a 24cM match the DNA alone isn’t going to point very strongly one way or another. Doing genealogy would be the step needed to verify your actual connection!

          Fingers crossed for finding that connection 🙂

          Reply
  8. Jill Hindley

    I am desperate to find my maternal grandfather. My mum has done a dna test and got a match of 2nd – 3rd cousin. With 318cM 5% shared DNA. What ancestors would they share?

    Reply
    • Diahan Southard

      Very cool! So there are a few factors, like how old this match is compared to how old your mom is, as we talk about in this post. If they are about the same age, they could be second cousins, sharing great grandparents. If the match is younger than your mom, they could be half first cousins once removed. So that means that this match’s great grandfather or great grandmother is your mom’s grandfather or grandmother. Does that make sense? So if you are looking for your mom’s father, then it would be the son of the couple you share.
      That sounds complicated when I write it out like that! This is something we could go over in a mentoring session, if you want help. http://www.yourDNAguide.com/thementor.

      Reply
  9. Melissa

    I have a first cousin once removed and we share 710 cm. How is he kin to me? I also just found out my brother is only my half brother.

    Reply
    • Diahan Southard

      Remember that there are several relationships that can correspond to the same amount o shared DNA. So at 710 cM this person could be your first cousin, your great grandchild, or your half niece or nephew, to name just a few possible relationships. So if this person is sharing DNA with your half brother, then the half-niece seems more likely, but if they don’t share with your half brother, then perhaps they are a first cousin. I go over how to find your relationship to a Mystery Match in my book, if you want more help. https://www.yourdnaguide.com/your-dna-guide-the-book

      Reply
      • Charlotte Nash

        I have a great uncle that shares 526 cm with a female that was adopted at birth and she is trying to find her family. The possibilities according to Ancestry.com indicates that she could be 84% my great uncle’s 1st coustin 1x removed or half cousin. My great grandmother only had 1 brother and he did not have any children. The adopted cousin shares 308cm with my mother, 139 cm with me, and 144 cm with my brother. I believe my great grandmother’s brother may have had a child and he was not aware of it.

        Reply
        • Diahan Southard

          Charlotte, these sensitive situations are tricky. There are a couple ways I could help you figure it out if we could look at the data together. It would be a good situation for a mentoring session (www.yourDNAGuide.com/thementor). But one thing to look at is the age of the person you match. If they are your great uncle’s age, then that lends to a half first cousin. But if the match is younger, then the first cousin once removed.

          Reply
  10. Mary Jeffrey

    I have a question if possible to answer. My half sister has a son two years younger than me. That would make him my nephew. We did a 23andme DNA, it came up that he is my cousin once removed, not my nephew. Does this mean my half sister and I have different mothers. I really hope you can answer this, I feel lost in space. Also, is it possible that my parents are not my real parents. Thank you, much appreciated.
    Mary

    Reply
    • Diahan Southard

      Mary,
      The first thing to remember is that the same genetic relationship, measured by the amount of DNA you share, can have DIFFERENT genealogical relationships. So, for example, the amount of DNA you share with your half sister is the same amount of DNA you would share with your aunt. So 23andMe could have just as easily called your half sister your aunt. They have an algorithm that tells them which relationship to put on the website, but it isn’t always the correct genealogical relationship.
      You are correct, your half sister’s son would be your HALF nephew. A Half nephew shares just about the same amount of DNA as a first cousin, but not a first cousin once removed. So I would want to look at the amount of DNA you share so I could double check it. But clearly you have a close relationship with him, we just need to figure out how. This would be a good subject for a classic mentoring session. You can learn more at http://www.yourDNAguide.com/thementor.

      Reply
  11. jo

    Trying to find my father. I matched with a first cousin 1R or 2nd cousin at 3.6 % 252.7 cm shared. Could his uncle be my father?

    Reply
    • Diahan Southard

      Hi Jo. You are on the right track. the first thing you need to do is decide how old this match is compared to you. If they are younger than you, then yes, the HALF 1C1R makes the most sense. But if they are your age, then second cousin is more likely. Either way, you are looking to connect at their great grandparents. This would be a good topic for a mentoring session. Check them out at http://www.yourDNAguide.com/thementor.

      Reply
  12. Tara

    I have a man in my family tree believed to be my first cousin. Our DNA shows him to be a first cousin once removed. I have other first cousins that share 10-11% DNA, but this one that is showing once removed shows just over 7% shared DNA.
    Is this possible, or do I have some family secrets?

    Reply
    • Diahan Southard

      Tara, this is a situation where I would want to look at all the data. But it sounds like you may have a different relationship to this cousin. That you may be half first cousins, instead of full. If you want, you can schedule a mentoring session http://www.yourDNAguide.com/thementor.

      Reply
  13. Marti

    Hi Diahan, I’m so glad I found your site. My husband is looking for his father and doesn’t have any info to start. He did AncestryDNA and matched with 1cousin removed or 2nd cousin 434 cM 6% shared DNA. The match is almost 20 years older than me. Would her Uncle or Great Uncle be his father?

    Reply
    • Diahan Southard

      Hi Marti. when a match is that much older, I would say you are once removed. At 434 the most likely once removed relationship is first cousins once removed. That means that one of your match’s grandparent couples is one of your husband’s great grandparent couples.

      Reply
      • Marti

        Thank you for the prompt response! Since one set of the match’s grandparents would be my husband’s great grandparents, does that mean that one of the match’s great uncles or uncle would be my husband’s father?

        Reply
      • Ginger Cameron Ford Crouch

        How can we ask private questions about ancestors of matches specifically for me its about who one of my great grandfather’s might be who wasn’t married to my great grandmother but more information I could ask in a private message if possible please ty!

        Reply
  14. JOAN L FRANK

    Hi- Enjoying the course but last video said to watch a Youtube about dots in Ancestry – But there was not link to that video in Resources that I could find.

    Also looked like you added a lesson about NEW Ancestry genetic ethnicity for the parents. But after doing the lesson I can not find it again to review and the Research log illustrated in that lesson is not in the Resource pdf.

    Thank

    Reply
    • Diahan Southard

      Here is the link to the Youtube video about using the dot system at Ancestry. https://www.youtube.com/watch?v=MRrEEDziYAs.

      The new lesson in the AncestryDNA Tour is under Unit #1 and it’s called Ethnicity Inheritance. There is an updated workbook in the workbook section as well.

      Reply
  15. leon

    I had a woman contact me from Asia stating she is my daughter. She was born 50 years ago.She has a DNA test results for “23 and Me” stating my a cousin of mine has a 2.11% match. Is this possible? Am I her father? I don’t know of her or her mother.

    Reply
    • Danielle Francis

      Hi Leon, without seeing the exact test results it’s hard to know what could be going on here. Probably the easiest way to figure out more would be for you to take a DNA test from whatever company she has tested at so you can directly compare exactly how much DNA the two of you share. This is much more reliable than comparing how much DNA she shares with one of your cousins. If you’d like help with understanding and interpreting your test results, I would recommend one of our mentoring sessions (https://www.yourdnaguide.com/thementor).

      Reply
  16. Valerie Renaud

    Hi Diahan,
    I stumbled on this site and am glad I did.
    I have done my DNA with both 23andme and Ancestry.
    I have been trying to find information on my biological fathers side.
    I have a 2-3rd cousin that shows up to be the closest so far. Many is set on private.
    With many months tracing his line, I have found that this cousin ‘s mother and my potential grandmother are sisters.
    My question is, how do I know if I am on the right path?

    Reply
    • Danielle Francis

      We recommend using DNA research and evidence like you would any other genealogical research and evidence, you’ll want several pieces of supporting evidence to back up any of your conclusions about relationships. If you have multiple DNA matches that indicate this relationship and/or records that support this, then you can have confidence in your results. If you’d like another set of eyes on our findings to double check your process, check out our classic mentoring sessions: https://www.yourdnaguide.com/classic-mentor

      Reply
  17. Anita

    I have a first cousin twice removed match to a gentleman who is 26 years older than me. He has shared his tree with me but I don’t know how to go about finding the common ancestor. I have several other 2nd cousin matches that I think I know the common great grandparent of but it doesn’t match with the first cousin twice removed match. What ancestor of my first cousin twice removed do I research to get to my biological mother of father match?

    Reply
  18. Dawn Paintner

    Hi my deceased aunt (moms sister .) show up as possible 1 st or 2 nd cousin . We share between 800 and 900 cm . My mom is also deceased and there were no dna sites before she passed . So I am thinking that my moms dad was someone else . My mom looks just like her mom , but also looks like her grandmother. Maybe my mom was my grandmothers child ?

    Reply
    • Danielle Francis

      You’re doing exactly the right thing, thinking of all the different possiblities that might explain your amount of cM shared with your aunt. Both scenarios you described are good hypotheses to investigate. Your best bet will be starting with finding out/ confirming the fathers of your mother and aunt. This article explains how you can start that process: https://www.yourdnaguide.com/ydgblog/what-is-genetic-network-dna

      Reply
  19. Robert Hanna

    My paternal grandmother was the oldest of 5 siblings. My father is the oldest of all his 1st cousins (there were 15) on that branch of the family. Among them they had about 30 children (my 2nd cousins). We range in age from 86 down to 59. I’m 81. If I didn’t know who they all were, it might seem that some were removed.

    Reply
    • kathleen Withers

      When I was reading your post, with all the cousins and age differences in your family tree, it really highlights the need to always add good old fashion research to your plan.. It really is the only way to unravel many of the relationships. I am working on finding a set of 3x great grandparents and I really need to be as sure as I can about every relationship I use as another building block leading back to my target couple.

      Reply
  20. Anne Marie Mc Donagh

    Hi since finding out through an Ancestry DNA test that my father isn’t my biological father (no matches) I have been constructing a paternal tree using my DNA matches on that line on Ancestry and also contacted a few o them, which proved helpful. I nw think I’ve identified him. But his grandaughter having taken the DNA test has shown as 1-2nd cousin (14% share DNA, 1,004cm across 28 segmets, longest 125cm) If I have identified the right father shouldn’t she show as half neice? She is younger than me – the same generation as my children. By comparison another DNA match 1-2nd cousin son of the identified father’s sister is a 7% dna match. I don’t understand how the grandaughter of a sibling group (my father is definitely one of them) can have double the amount of shared DNA and yet be a generation further down the line?

    Reply
    • Diahan Southard

      There are several relationships that can correspond to the same amount of shared DNA. While Ancestry lists matches in broad categorie large ranges, like 1C-2C, you can click on the amount of shared cM shown in blue and see the percentage probabilities for different relationships.

      Based on your theory, you share more DNA with the younger ‘granddaughter’ because you have a closer common ancestor – the man you think is your biological father. You share a more distant common ancestor(s) with the 7% DNA match – your/his grandparents (full first cousin) or just one person from the grandparent couple (half first cousin).

      A premium mentoring session would be a great opportunity for you to have an expert evaluate your theory and provide you with some next steps to help verify this very important conclusion! http://www.yourDNAguide.com/thementor.

      Reply
  21. Treasa Stringer

    My mother was sent away to another state to live with strangers at the age of 5. She didn’t know her mother as her mother had just died, she only knew her father’s and 3 siblings names. I have a lot of close matches that are on her maternal side I believe. I can’t find the person that connects my grandmother to anyone in my matches’ tree. I can’t find any information on my grandfather as far as his parents or siblings go, so I’m not sure about any matches to him. I have a lot of gaps in my tree because of this, hoping one day to find that missing link. But I do not know what to do now.

    Reply
    • Diahan Southard

      The first step you’ll need to take is to use shared matches to create genetic networks. From there you’ll need to build out your matches’ trees until you find a common ancestor between all of them, that will be your shared ancestor. Our Book, Your DNA Guide – the Book, explains the whole process in detail, I would recommend using that to help you. It’s available in print and digital form here.

      Reply

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