About Us
CousinChart.com exists to answer one deceptively hard question: wait, how are we related?
Every family has that moment. Someone brings a new baby to a reunion and nobody can agree whether she's a second cousin or a first cousin once removed. A DNA test comes back with a stranger sharing 680 centimorgans and no explanation of what that means. Somebody needs a family tree for a school project by Tuesday. We built the tools we wanted in those moments — instant, visual, free, and actually fun to share.
What you can do here
- Relationship Calculator — work out any blood, step, or in-law relationship and see it drawn as a chart, with everyone's real names and photos on it. It answers both directions, because you are something to them too.
- DNA Match Calculator — turn the shared centimorgans (cM) from an Ancestry, 23andMe, MyHeritage, or FamilyTreeDNA match into the relationships that are actually possible.
- “What Do I Call…?” — the in-law, step-family, and half-relative terms that plain cousin math doesn't cover: your aunt's husband, your child's in-laws, your step-grandmother.
- Printable Family Trees — blank charts to print and fill in by hand, or a photo version you can turn into a keepsake.
And a library behind them
The calculators answer the question in front of you. The guide library is for everything that comes next — more than 300 plain-English articles covering:
- Cousins and kinship terms — removed, half, double, step, grandaunt vs. great-aunt, niblings, and the cousin marriage laws people are usually too embarrassed to look up
- DNA matching — centimorgans, triangulation, shared matches, the Leeds Method, mirror trees, endogamy, and what ethnicity estimates can and can't tell you
- Records research — U.S. census years from 1850 to 1950, immigration and naturalization files, vital records, church and court books, military service, plus country guides for Ireland, Italy, Germany, Poland, Mexico, Quebec, and more
- Surname origins — where a last name comes from, why its spelling changed, and what patronymic and occupational names reveal
- Charts and templates — pedigree, fan, bow-tie, ahnentafel, genogram, kinship, and family group sheets, in printable and editable formats
- Keeping the story — interviewing relatives, preserving photos and heirlooms, planning a reunion, and writing a family history worth passing on
Free, and private by design
Every tool here is free and needs no account. More importantly, it runs entirely in your browser. The names you type and the photos you add to a chart never leave your device — there is no upload, no server-side copy, and nothing for us to lose. Close the tab and it's gone. That matters more than usual here, because a family chart is personal information about people who never agreed to be on a website.
How we try to get it right
Relationship terms sound fuzzy, but they aren't. Our calculator follows the standard genealogical rules for cousinship and removal — the same ones professional genealogists use — rather than the folk version that turns every distant relative into a “second cousin twice removed.” Our DNA ranges are built on the widely cited Shared cM Project, the crowdsourced dataset of real tested relationships, so the possibilities we show you are the ones actually observed rather than what the textbook average predicts.
Guides are written in plain American English, checked against primary sources where they exist, and updated when something changes. We would rather tell you “this varies” than invent a tidy answer.
One honest limit: cousin marriage law, inheritance, and citizenship by descent all vary by state and country, and they change over time. Our articles explain how those rules generally work so you know what to ask — they are not legal advice, and nothing here about DNA is medical advice. For a decision that matters, talk to a professional in your own jurisdiction.
Who's behind it
CousinChart is a small independent project, part of the FriendlyApps family of free tools. There is no venture funding and no data business behind it — the site is supported by advertising, which is what keeps every tool free and account-free for everyone.
Tell us when we're wrong
Family relationships are full of edge cases, and we would much rather hear about one than leave it wrong: a term your family uses that we've missed, a chart that breaks, a law that has changed, a guide that could be clearer. Write to us on the contact page — a real person reads it.