Finding cousins who still live in the Czech Republic, Slovakia or a Czech and Slovak settlement in America is one of the best things a DNA test can do, because a cousin’s tree can save you years of archive work. It can also be hard, because you cannot know in advance how many relatives have tested. This guide sets realistic expectations, shows how to give yourself the best chance and offers a message in English, Czech and Slovak. We checked these details in October 2026, and company features, database sizes and prices change often, so confirm them before you buy.
Set realistic expectations
We did not find reliable figures on how many people in Czechia or Slovakia have taken a consumer DNA test, so we cannot say how many matches to expect there. What we can say is that distant matches are uncertain. The Shared cM Project, which collects the amounts of DNA shared by people with documented relationships, gives these approximate figures:
| Relationship | Average shared DNA (cM) | Typical range (cM) |
|---|---|---|
| First cousin | 866 | 396 to 1,397 |
| Second cousin | 229 | 41 to 592 |
| Third cousin | 73 | 0 to 234 |
| Fourth cousin | 35 | 0 to 139 |
| Fifth cousin | 25 (among those who share DNA) | 0 to 117 |
For distant relationships the averages include only people who shared DNA, and the statistics do not account for pedigree collapse or endogamy. If your Czech or Slovak ancestors left more than a century ago, your cousins in Europe are probably fourth or fifth cousins or further. Use the Shared cM Project tool to compare any match with the ranges.
Step 1: Test where cousins test
MyHeritage is our first suggestion, because an independent review says it has European relatives that other databases lack and because you can build your tree there. It no longer accepts uploads, so you must take its test to be in its database, and then you can transfer the results to FamilyTreeDNA and GEDmatch for free. If your known relatives are mostly in North America, AncestryDNA’s large database may also be worth a test, and 23andMe’s Early Czech Americans groups may connect you to a settlement community. See the best DNA test for Czech and Slovak ancestry.
Step 2: Test your older relatives
Test the oldest generation you can, since they share the most DNA with your older ancestors, and test siblings, aunts, uncles and cousins, because each inherits different segments. First and second cousins also help you work out which side a match belongs to.
Step 3: Add a tree with Czech and Slovak details
A tree gives matching tools something to work with. Add the village, the parish, the house number if you have it, the masculine and feminine surname forms and the spellings with diacritics. See our village-of-origin guide and our spelling guide.
Step 4: Sort your matches
- Look at the amount first. An amount around 70 cM or more is consistent with a third cousin or a closer relationship.
- Check the country shown for the match, and look for Czech, Slovak, Hungarian, German and Rusyn place names in the tree.
- Use shared matches. They show which matches are related to each other.
- Use clustering tools. MyHeritage’s AutoClusters group matches who likely descend from common ancestors.
Step 5: Read the tree with Czech and Slovak naming in mind
A woman appears under the feminine form of her surname, a Hungarian and a Slovak spelling may refer to the same family, and diacritics may be missing. Search the masculine and feminine forms and the stem. See our guide to women’s surnames and our guide to surnames changed in America.
Step 6: Write a good message
Keep it short and specific, include the amount of DNA you share and a village, and ask one question. Here are samples. Have a Czech or Slovak speaker check the translations before you send them.
Illustrative composite (not a real family): English: “Hello, we share about 74 cM of DNA, which suggests a fairly distant cousin. My ancestors came from the village of [village]. Do you have any ancestors from that area? I would be glad to share my tree.” Czech: “Dobrý den, sdílíme přibližně 74 cM DNA, což ukazuje na vzdálené příbuzenství. Moji předkové pocházeli z obce [obec]. Máte předky z této oblasti? Rád bych se podělil o svůj rodokmen.” Slovak: “Dobrý deň, zdieľame približne 74 cM DNA, čo naznačuje vzdialené príbuzenstvo. Moji predkovia pochádzali z obce [obec]. Máte predkov z tejto oblasti? Rád by som sa podelil o svoj rodokmeň.”
Expect that some matches will not reply. Some tested out of curiosity and never log in again. Be patient, be polite and do not send repeated messages.
Step 7: Use projects and surname resources
- FamilyTreeDNA accepts free transfers and hosts group projects. The Carpatho-Rusyn Heritage DNA Project welcomes males and females of Carpatho-Rusyn heritage, and the Lanškroun Region DNA Project, run by an administrator who says he looks for men whose paternal line comes from that part of Czechia, uses Y-DNA to link old local family lines.
- Slovak surname databases. Cyndi’s List describes a Slovak Pride Database with 30,000 Slovak surnames and their villages of origin, and a Slovak Surname Location Reference Project that records where descendants of Slovak immigrants can be found in North America.
- GEDmatch accepts free uploads, which puts you in a database alongside testers from other companies.
- A Y-DNA test can help with a male line. See the FamilyTreeDNA options in our comparison.
Step 8: Respect other people’s data
A match has shared a name and a tree under the company’s terms, not for public posting. Do not post another person’s tree or results publicly without permission, and remember that DNA results reveal information about relatives.
If DNA does not deliver
Lean on the records. Use the tracing guide, the Czech parish registers guide and the Slovak records guide to find living cousins through documented families, and try again as more people test.
Common mistakes
- Expecting close European matches. Most will be distant.
- Sending a vague message. Give the amount and the village.
- Testing only yourself. Older relatives carry more.
- Ignoring surname forms. Search masculine, feminine and variant spellings.
- Posting a match’s tree publicly. Ask permission first.
Continue with connecting DNA matches to Czech and Slovak records and the DNA testing hub, and browse DNA & Tools. Sources include a 2026 DNA test review in Who Do You Think You Are? magazine, the Shared cM Project tool, Cyndi’s List on Czech and Slovak peoples and a post by the Lanškroun Region DNA Project’s administrator.
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