Read the Family Tree beginner guide to DNA genealogy and understand the popular tests
Want to uncover your family’s story through DNA? Taking a DNA test for ancestry can open the door to long-lost relatives, hidden heritage, and exciting family history discoveries. In this beginner’s guide, genealogist Karen Evans explains how autosomal DNA tests work, what your ethnicity estimate really means, and how to interpret DNA matches. We’ll also compare the best DNA tests for family history so you can choose the right one and start building your DNA family tree today.
Quick links
How much to ancestry DNA test kits cost? Black Friday offers?
How to take an ancestry DNA test kit
How long for DNA test results to come back?
How large are genetic genealogy databases?
Why is the size of the DNA database important?
I've bought a DNA test, what do I actually get?
Do you need to pay extra at DNA genealogy testing companies?
What tools do genetic genealogy companies provide?
Learn about grouping and colour-coding
Which DNA companies provide online tree-building tools?
Do I need a chromosome browser?
Relationship calculator for DNA
How accurate are ethnicity estimates?
ThruLines, Common Ancestor Hints & Theories of Family Relativity?
Pros & cons of DNA testing companies
What were Karen Evans' experiences of starting with genetic genealogy and taking a test?
I thought about taking a DNA test for years. My paternal grandfather was illegitimate and so was a great-grandmother and her mother! But I hesitated.
If I’m honest I wondered whether spending that amount of money would be worth it and, more importantly, whether it would help with any of my ‘missing father’ brick walls.
I watched as prices slowly began to fall and the choice in tests grew. I finally took the plunge in 2017 at a family history show where there was a tempting, too-good-to-resist offer on a FamilyTreeDNA test. And, oh what an exciting, educational and sometimes frustrating area of genealogy it opened up!
Goodness, I was naïve, having done little DNA research despite being a long-standing family historian. It was a steep learning curve and I made mistakes but, ultimately, I’m so glad I took that first step.
So here is my (hard learned) take on the tests available and the pros and cons they have.
I won’t be covering Y DNA or MtDNA tests here. Instead, I’m focusing on autosomal tests which are the most popular DNA tests taken by family historians from the following companies:
Let’s dive into the details!
How much do ancestry DNA test kits cost? Black Friday offers?
Prices vary. Sales are frequent and the discounts are often very good. If possible wait for the sales. The non-sale prices are: 23andMe £89, Ancestry £79 plus shipping (£9.99 for one kit and then £4.99 for any additional kits ordered at the same time), FamilyTreeDNA £60 (depending on conversion rates from dollars to sterling), LivingDNA £99 and MyHeritage £79 (plus shipping).
Prices vary greatly depending on the time of year. Many of the companies offer discounted tests around Christmas and Black Friday; Mother’s Day and Father’s Day are also popular times to drop prices.
Some of these companies require a subscription to access all the tools (see below) so this needs to be factored in.
How to take an ancestry DNA test kit
You need to buy a kit and supply a saliva or cheek swab sample then send off your kit. The results will be supplied to you online.
Whichever company you use they will need a sample of your DNA. Some companies (23andMe and Ancestry) ask for a small vial of your saliva, the others (FamilyTreeDNA, MyHeritage and LivingDNA) require a cheek swab. Both methods are painless and all the companies give clear instructions on how to take a sample. Be aware that many elderly people find it difficult to provide saliva but there are tip and tricks online to help them provide a sample.
How long for DNA test results to come back?
Expect it take at least a month to get your DNA genealogy test results back.
I often see people on social media ask how long it will take before their results to come through once they have sent their sample. The simple answer is…it all depends.
If you are in the UK and take an AncestryDNA test, for example, you may notice the return address on the box is for Ireland. It does go to Ireland but is then shipped to the US, and I have known this to take a month before it begins processing. If you send a test off just after Christmas the wait will probably be longer as all the people who had a test as a present are sending theirs off too! The quickest turnaround (post box to results) I’ve had is sixteen days; the longest was nine weeks.
How large are the genetic genealogy databases?
AncestryDNA has the largest database of DNA matches - more than 25 million people have tested with AncestryDNA. MyHeritageDNA has approx 9.3 million. FamilyTreeDNA approx 1 million.
Why is the size of the DNA genealogy database important?
The size of the DNA testing company's database is an extremely important factor when buying a DNA test.
The more people in the database of the DNA company with which you test, the greater the chance that you will find matches, which will help with your research question.
The chart created by Leah Larkin (The DNA Geek) shows a clear winner when it comes to the size of DNA database: Ancestry. At more than 25 million people in its DNA database, it has more people than all the other testing companies combined. How does that translate into matches?
Let’s compare: size of database & number of DNA matches
I did a quick experiment with my mom’s results and counted how many matches she had in each database that shared 30cMs or more with her.
Why 30cMs? Well, these are the matches who most likely share a common ancestor with you and can be found using traditional paper research. This isn’t to say matches below 30cMs are impossible to research (I have been able to add many to my tree), but when you start off, the higher matches (ie those which share more cM with you) are typically the easier to research.
What’s a cM/centiMorgan - when talking DNA genealogy?
A cM is a centimorgan. It’s a unit of measurement for a segment of DNA. Typically the larger the segment you share with a DNA match, the more closely you are related. You are more likely to share a greater number of segments with closer DNA matches too.
So drumroll… To follow are the number of matches (at 30cMs or more) that my mom had at each of the companies:
• Ancestry 166 matches
• MyHeritage 117 matches
• 23andMe 103 matches
• LivingDNA 42 matches
• and FamilyTreeDNA 10 matches.
These numbers don’t tell the whole story though. Let me explain.
What does 'downweighting' mean for DNA test results?
Ancestry uses an algorithm called Timber which downweights segments of DNA that it believes may be shared for a reason other than a common ancestor. This is not something the other companies do and is one of the reasons why the same match on two different databases will share a different amount of DNA with you.
Mom has lots of matches which show below 30cMs but their unweighted total is 30cMs or more.
Below is an example showing how AncestryDNA displays the unweighted shared DNA between you and a match.
I’ve bought an ancestry DNA test kit, what do I actually get?
You will receive access to a database of DNA matches, DNA maps to illustrate your origins, and DNA tools to help you begin investigating your DNA matches.
Your database of DNA matches
Once you have registered your kit, provided your sample, and your test has been processed you will receive an online database of your matches.
Your online database of your matches will include a name (or alias) of the match and, depending on the company, information and tools which will help you find the connection.
All the testing companies tell you how much DNA you share with a match. It is given as a number in centimorgans or cMs (except for 23andMe who use a percentage).
• Ancestry, MyHeritage and FamilyTreeDNA put the matches in order, with the most number of shared cM at the top, going down to the least.
• 23andMe use a slightly different format and look at the percentage and segment amount to work out the strength of the relationship. I click on ‘percent related’ to place them in a format I’m more used to.
• LivingDNA put your matches by degrees of separation, and this will also (like 23andMe) alter order from strictly the amount of DNA shared.
How to message DNA matches
All the companies provide a DNA match messaging service. This is usually through the site itself but FamilyTreeDNA give testers the option to provide an email address so matches can make contact directly, which I’ve found very helpful.
Do you need to pay extra at DNA genealogy testing companies?
The access you get to the DNA testing companies' websites varies. Very often, in addition to having purchased a DNA genealogy test, you will also need to buy some sort of paid membership or pay some sort of add-on fees in order to access more of the tools for the DNA testing company you are using.
When the sites are fully operational the DNA tools and resources available include such things as: a match list; a chromosome browser; surnames of interest; and relatives in common (or a shared matches facility which allows you to group matches to find a common ancestor).
Only FamilyTreeDNA and 23andMe allow access to their whole site without needing to pay for upgrades/add-ons.
LivingDNA does not require a subscription to access its match list and tools but offers paid add-ons comparing your DNA to groups such as Vikings, for instance.
AncestryDNA is a little more complicated. You need a paid membership to gain access to your shared match list and most tools. This can be a family history membership to Ancestry, or Ancestry also offers an AncestryDNA Plus membership. A regular Ancestry family history membership will give access to everything without the need for the AncestryDNA Plus membership. Ancestry Pro Tools subscription too (£7.99 per month, paid monthly, over and above any other Ancestry membership you may have) provides access to additional tools - most usefully and importantly 'enhanced shared matches'.
So that leaves MyHeritage. I love their DNA site but you cannot access many of its features without a subscription. This includes the shared matches facility or your match’s tree. Although you can still use your match list, it makes it difficult to discover their connection.
What tools do genetic genealogy testing companies provide?
DNA genealogy testing companies provide tools such as details of your shared matches, tools to help you put your DNA matches into groups that share DNA with one another, family trees of you DNA matches and family tree building tools. Each DNA testing website provides a different selection of tools. AncestryDNA and MyHeritage lead the way with tools and this shows in my discoveries.
Tools really are a game changer in helping you discover how you and a match may be related. I have occasionally found a connection using a match’s name only, but this is much more difficult and not to be expected at all.
As I say, AncestryDNA and MyHeritage lead the way with tools and this shows in my discoveries.
Of the 161 4th cousins or closer I have found on my maternal line, the majority are from AncestryDNA, 18 from MyHeritage, 6 from 23andMe and 4 from FamilyTreeDNA.
So here are a list of some of the tools that companies offer to help you with your matches.
What are shared matches?
A 'shared match' is someone that you and one of your DNA matches both share DNA with.
LivingDNA call 'shared matches' 'family matching', FamilyTreeDNA call it ‘in common with’ but – whatever it’s called – it is one of the main tools in your DNA armoury.
Put simply if you know how a match fits into your tree then shared matches with this person are likely to come from the same part of the tree.
As an example: I have a half cousin who shares a grandparent with me. Our shared matches come from this grandparent’s line. With MyHeritage you need a subscription or unlock payment to view it, and with AncestryDNA you need an Ancestry membership or AncestryDNA Plus membership to view all your shared matches.
Learn about grouping & match labelling to colour-code your ancestry DNA matches
Colour-coding your DNA matches enables you to group matches together into possible ancestral lines. It goes hand in hand with shared matches. The ‘coloured dots’ are currently available on AncestryDNA, MyHeritage and LivingDNA.
Below is an example of some of the groups that Karen has created for her Mom on AncestryDNA.
How to understand DNA matches and shared DNA segments
Your DNA match list will show how much DNA you share with each of your matches, as mentioned above. There is a wonderful tool available on MyHeritage and 23andMe, and (if you have Ancestry Pro Tools) on AncestryDNA too, which also allows you to see how much DNA a match on your list shares with another match on your list. This is fantastic because it can show two matches are, for instance, mother and son or closely related, thus helping with possible research.
Which DNA testing companies provide online tree-building tools?
As you would expect the two companies (Ancestry and MyHeritage) which offer records to research your family history also have great tree-building tools in their DNA package.
Ancestry and MyHeritage both encourage testers to attach a tree to their results and offer additional tools with this.
FamilyTreeDNA offers a tree building facility to testers which are attached to their results for matches to access (learn more here). As of June 2025 testers may also connect their WikiTree tree to their FamilyTreeDNA test results (learn more here).
LivingDNA and 23andMe do not offer tree building tools. Although 23andMe do offer you the opportunity to link a tree from another site in the ‘Family Background’ section, very few matches do so.
How can a chromosome browser help me with DNA?
A chromosome browser is a more advanced DNA genealogy tool which shows where you and your match share the segments of DNA on one or more of the pairs of chromosomes. It can be useful for identifying matches who share the same ancestors (using triangulation) and is used to build up your personal chromosome discoveries.
MyHeritage and FamilyTreeDNA have chromosome browsers at the moment, 23andMe have disabled theirs. [This was due to a data breach in the Autumn of 2023].
Relationship calculator for DNA genealogy
Each company provides a relationship guide to help you determine how someone may be related to you.
- AncestryDNA and MyHeritage give you a list of possible relationships but also how probable they are. MyHeritage tend to give the most probable next to the match which makes testers think that is the actual relationship.
- MyHeritage( again) along with 23andMe and LivingDNA provides a visual relationship guide, pointing out places on the tree where your match may fit.
- FamilyTreeDNA simply gives a relationship range such as 2nd-4th cousin which is very vague.
How accurate are ethnicity estimates from DNA tests?
The ethnicity part of your test will be accurate at a continental level but then narrowing to specific countries is more difficult. Note that ethnicity estimates are updated and evolve over time. Many of the tests do give a regional breakdown, indicating which areas you share with your matches. My family are from the Midlands and that is reflected in their ‘genetic groups’ (MyHeritage and 23andMe) or ‘regions’ and 'sub regions' (AncestryDNA). These regional breakdowns do reflect papertrail family history research much more closely.
Many of your matches will not be family historians but will have taken a DNA test to find out where they came from (or whether they are an Indigenous American if they are in the US or a Viking if they live in the UK!). My son is (currently) 35% Scottish, according to AncestryDNA but his tree (verified with DNA) shows no Scottish ancestors in the last six generations. If you expect to be only European and the test shows you 20% African then it may give you an area of research but use your DNA matches to indicate specific countries.
Unique DNA genealogy tools from DNA test kit companies
Below are some tools which are specific to one company and worth mentioning.
Thrulines, Common Ancestor and Theory of Family Relativity
Though not strictly unique to one company it is worth mentioning these in more detail as they really can be helpful. Both AncestryDNA and MyHeritage utilise the trees on their site (along with record sets) to create tools. AncestryDNA offers common ancestor, Thrulines and shared surnames, while MyHeritage offers ‘Theory of Family Relativity’ and shared surnames.
Thrulines and Theory of Family Relativity look for common ancestors in your tree and your match’s tree to find how you may be related and then presents them, showing the path between you and the match. This can save a great deal of time in your research, particularly when they don’t need the common ancestor to be on the trees you have created!
Sometimes these paths are spot-on. However trees online can be, and frequently are, wrong. People often copy trees they find and add them to their own without checking information. This can create a link between you and a match which is incorrect.
Both Thrulines and Theory of Family Relativity are guides to common links but always do your own research to verify the trees involved.
On MyHeritage you can confirm or reject the theory but this option is not available on AncestryDNA’s Thrulines.
Using AncestryDNA’s SideView tool to separate maternal & paternal matches
This appeared on AncestryDNA in 2023 and was something of a wow moment!
SideView splits your matches into Parent 1 and Parent 2 without the need for either parent to test. This meant that if I knew that ‘Alex’ was from my mom’s side and had been given the Parent 1 label, then Parent 1 was my maternal side. Even if you don’t know which parent it is, SideView can already divide your matches into two groups. I have personally found SideView to be very accurate.
Family Tree
23andMe made rather a bold move and created a tree based on whether closer matches are one parent or the other and where they might fit in the tree, again without parents having to test. The tree can be altered if needed, adding matches or moving their position. The tree was fairly accurate on grouping matches to one side or the other but less successful on positioning.
Autoclusters
MyHeritage tools include an autocluster facility which automatically clusters your matches into groups. This could save precious time looking for a common ancestor or ancestral couple in a group. An autocluster tool on AncestryDNA is being rolled out through 2025.
Ease of use & glitches - the pros & cons of the DNA genealogy testing companies
All the companies try to make their databases user friendly, often offering help pages and videos but here are a few things that I’ve noticed:
All sites can have their moments but both LivingDNA and FFamilyTreeDNA can be slow to load their database and the tree facility on FamilyTreeDNA is very glitchy (for instance, buffering and taking time to generate your match list).
You may have noticed earlier that, although MyHeritage’s database is around seven million compared to AncestryDNA’s 25 million, my mom had a lot of matches over 30cMs. Why could that be? Many people report false matches on MyHeritage. A false match is someone who is not related to you via a common ancestor. All databases have false matches, but they are usually matches who share only a small amount of DNA. I have tested my son, myself and his father so if he has a match they should be a match to me or his father as DNA can only be inherited from your parents. Any of our son’s matches who don’t match one of us is a false match. His highest false match on MyHeritage shares 58.1cMs with him but isn’t on either of our match lists. There are several reasons why there are high false matches on MyHeritage (including uploading) so it is something to factor in – simply consider setting a higher threshold for the number of cM shared between you and a match. For instance, by concentrating on DNA matches above 60 or 70cM.
Pros and cons - Ancestry DNA testing
Pros: largest database by far with a range of helpful tools
Cons: won’t accept uploads and you need some kind of subscription to access all the facilities
Pros and cons - 23andMe DNA testing
Pros: large database and has how matches match facility
Cons: very few tools and no viewable trees onsite
Pros and cons - MyHeritage DNA testing
Pros: really great range of tools.
Cons: some matches are false (so simply adjust your cM threshold, above which to search) and you will need a subscription to access the tools if you buy a test from them. As of August 2025 MyHeritage DNA no longer accepts uploads
Pros and cons - FamilyTreeDNA testing
Pros: company has been selling DNA tests the longest so may find testers on their database who are not on any others. They accept uploads
Cons: relatively small database and limited tools
Pros and cons - LivingDNA testing
Pros: allows uploads and has match labelling
Cons: small database and no family trees connected to matches
Top Tips
Making the most of your money - autosomal DNA tests
AncestryDNA and 23andMe do not allow uploading so if you want to be in their database you need to buy their test.
MyHeritage used to allow uploads but through 2025 the situation seems to be changing and the upload option is being removed from some MyHeritage users.
FamilyTreeDNA and LivingDNA do allow uploads so you could buy a test from AncestryDNA or 23andMe, download the raw data and then upload to the other sites. You do have to pay an unlock fee to access the tools when you upload (about £30) but that is cheaper than buying a kit.
If you do decide to buy a DNA kit, wait for the sale prices.
To save extra money why not find a friend/relative who wants to get a kit and purchase on one order, thus saving some shipping fees. Use cashback sites like TopCashback and Quidco to get cashback on your purchase.
Historically MyHeritage allowed uploads and about once a year offered a free unlocking of the tools for life. My top tip would be to wait for the free unlock, upload your DNA to the company and you then have DNA matches, access to all their wonderful tools and no subscription to pay. This tip is dependent on MyHeritage offering the free upload and the free unlocking of the tools for life - but it's worth keeping an eye out for.
Getting ready for your results & learning more about DNA
Once you decide on a DNA test use the time waiting for your results wisely – get your tree up to date and check for accuracy. I know I’ve found mistakes on mine so it is a good idea to give it a spring clean and check it from roots to bud!
Grow your DNA knowledge & understanding
Watch videos and read up on using your test company to get the best from your results. MyHeritage have a Knowledge Base for example which has compiled short videos on many aspects of its DNA test.
Understanding how you may be related to a match based on shared DNA is so helpful, giving clues to where they may sit in your tree. If you are using AncestryDNA then use their relationship calculator, but for other companies I tend to use the Shared cM Project on DNA Painter This tool is also handy for changing a percentage of DNA shared to a total number of cM shared.
Remember: Ancestry’s Timber algorithm can downweight the DNA amount you share with a match. If you are on several sites and so is your match you will notice differences in the total amount you share. For example, here are the amounts my father and his half grand niece share on the different platforms: Ancestry 549cMs, 23andme 571cMs, FamilyTreeDNA 585cMs, LivingDNA 600cMs and MyHeritage 602cMs. This is perfectly normal and doesn’t mean a database is faulty. For lower matches you may even find that you match on MyHeritage but not on Ancestry even though you are both in the databases.
Explore the programme of online talks at Family Tree - many of which cover DNA!
And finally, have fun! Any mistakes you may make when experimenting with your ancestry DNA test results can be corrected and be sure of the fact that the companies continue to add new features and developments to aid you with your DNA journey.
ABOUT THE AUTHOR
Genealogist and author Karen Evans is the DNA news anchor at Family Tree's DNA Club. Karen also writes the monthly DNA Workshop articles in Family Tree and has published two ‘Grim Almanac’ books for History Press. Karen enjoys using DNA to resolve her own family mysteries and that of clients. In other historical pursuits, she also enjoys Regency dancing. If it has anything to do with history, she’s interested!
FAQs about DNA testing for family history
What is the best DNA test for ancestry in the UK?
For finding relatives, AncestryDNA has the largest database. MyHeritage has a large database of European-heritage testers.
What is a centiMorgan (cM) in DNA testing?
A centiMorgan is a unit used to measure the length of shared DNA segments — helping estimate how closely two people are related.
How long does it take to get DNA test results?
Most companies deliver results within 4–8 weeks after receiving your sample.
Can a DNA test help me find relatives?
Yes - you and your relatives will need to be in the same company’s database.
Note: this guide concentrates on autosomal DNA tests. We will provide guidance on Y-DNA tests and mtDNA tests in other blog posts.
This article was first published in the May 2024 issue of Family Tree. Blog last updated August 2025.
