What is a cousin chart?
A cousin chart is a quick-reference grid that names how two relatives are related by counting back to the ancestor they share. Find the closest ancestor the two people have in common, count the generations down to each person, and the chart names the exact relationship — first cousin, second cousin once removed, and so on.
Two rules do all the work. The ancestor two people share decides the cousin number, and the difference in their generations decides how many times the relationship is “removed.” Once you can see both at a glance, every label on the chart makes sense — and you never have to guess again at a family reunion.
Prefer to skip the counting entirely? Our free family relationship calculator names any relationship instantly and draws a personalized chart you can print or share — everything runs in your browser.
| The closest ancestor you both share | Your relationship |
|---|---|
| Grandparents | First cousins |
| Great-grandparents | Second cousins |
| Great-great-grandparents | Third cousins |
| Great-great-great-grandparents | Fourth cousins |
What counts as a cousin?
Cousins are relatives who share a common ancestor but aren't your direct ancestors, descendants, or siblings — and aren't the aunts, uncles, nieces, or nephews one clean generation away. If the only way you connect is through an ancestor you both descend from along different lines, you're cousins of some degree.
That definition rules a lot of relatives out. Your sibling shares your parents but isn't a cousin. Your aunt is your parent's sister — a direct one-generation step, not a cousin. Cousins branch sideways: two or more separate lines of descent from the same ancestor. Everyone on those side branches is a cousin, and the degree and removal only describe how far along the branches they sit.
So the first question to ask about any relative is never “how close do we feel?” but “who is the most recent ancestor we both descend from, and by how many steps?” Answer that and the label falls out automatically — which is exactly what a cousin chart, or the relationship calculator, does for you.
What does “removed” mean?
“Removed” measures the gap between two people's generations, not how close they are. Each “removed” equals one generation of difference. Your first cousin's child is your first cousin once removed — one generation down. Your grandmother's first cousin is your first cousin twice removed — two generations up.
The word trips people up because it sounds like it measures closeness, when it really measures a difference in generations. Cousins in your own generation are never “removed”; the moment there's a generation gap, the removals start counting. For a worked example, see what a first cousin once removed is.
- Your first cousin's child is your first cousin once removed — one generation below you.
- Your parent's first cousin is also your first cousin once removed — one generation above you.
- Your grandparent's first cousin is your first cousin twice removed — two generations above you.
First cousin once removed vs. second cousin — what's the difference?
They are not the same. A second cousin shares great-grandparents with you and sits in your own generation. A first cousin once removed shares grandparents with one of you but sits a generation above or below. The depth of the shared ancestor makes a cousin “second”; a generation gap makes a cousin “removed.”
| Relationship | Closest shared ancestor | Same generation as you? |
|---|---|---|
| First cousin | Grandparent | Yes |
| First cousin once removed | Grandparent | No — one generation apart |
| Second cousin | Great-grandparent | Yes |
| Second cousin once removed | Great-grandparent | No — one generation apart |
A simple test: if you and your relative are the same number of steps from the ancestor you share, you're plain cousins (first, second, third). If one of you is further from that ancestor than the other, you're “removed” by the difference. Compare the two side by side in first cousin once removed vs. second cousin.
How do you count first, second, and third cousins?
Count how many “greats” are in the ancestor you share. If your closest common ancestor is a grandparent, you're first cousins. A great-grandparent makes you second cousins; a great-great-grandparent makes you third cousins. Add one cousin degree for every extra generation back to the shared ancestor.
- Share grandparents → first cousins.
- Share great-grandparents → second cousins.
- Share great-great-grandparents → third cousins.
- Share great-great-great-grandparents → fourth cousins, and so on.
This is why “distant cousins” really are distant: a fourth cousin shares a five-greats-ago ancestor with you, which is why DNA between fourth cousins is often too faint to detect. See what a second cousin is for the next step up from first cousins.
What is a half cousin?
Half cousins share only one grandparent (or great-grandparent) instead of two, because the sibling link in the older generation is a half-sibling. Half first cousins descend from two half-siblings, so they share a single common grandparent. In practice half cousins are treated exactly like full cousins — the “half” only describes how much ancestry they share.
Half relationships appear whenever a shared ancestor had children with more than one partner — common in records with remarriage after a spouse's death. DNA testing often surfaces them because a half first cousin shares roughly half the DNA of a full first cousin. See what a half first cousin is for the exact definition.
Half relationships matter most when you're working backward from a DNA match. A predicted “first cousin” who shares only about half the expected DNA is often a half first cousin — a clue that a shared grandparent had a second family. Following that thread in the records is frequently how a previously unknown branch gets discovered.
What is a double cousin?
Double first cousins happen when two siblings from one family marry two siblings from another family. Their children share all four grandparents instead of two, so genetically they're as close as half-siblings — far closer than ordinary first cousins, even though the family label is still “first cousins.”
Double cousins were common in small, rural communities and can throw off DNA estimates, since the shared centimorgans look like a much closer relationship. They're a good reminder that the family word for a relationship and its genetic closeness don't always line up.
You'll usually spot double cousins in the tree, not the DNA: two marriages linking the same two surnames in the same generation. When you find that pattern, expect the descendants' DNA matches to read one relationship level closer than the paper trail says — a genuine result, not an error, once you know both couples were siblings.
What are great-aunts, grand-uncles, and other non-cousin relatives?
Not every relative is a cousin. Your grandparent's sibling is your great-aunt or great-uncle (sometimes called grand-aunt/grand-uncle). Their children are your first cousins once removed, and their grandchildren are your second cousins. These “avuncular” relationships sit alongside the cousin lines rather than on them.
This is where a chart earns its keep, because the labels stop being intuitive. See what a great-aunt is and let the relationship calculator name the in-between relatives the chart alone can't.
A worked example: naming a relationship step by step
Say you and a DNA match both descend from the same great-grandparents. You are three generations down from that couple; the match is only two generations down. The shorter path (two generations) sets the cousin degree, and the one-generation difference makes it “once removed.” You are first cousins once removed.
Work any relationship in three steps. First, find the most recent ancestor you both descend from — here, the great-grandparents. Second, count the generations from that ancestor down to each person: three for you, two for the match. Third, take the smaller count to set the cousin degree, and the difference between the counts as the number of removals.
Change one number and the label changes. If the match were also three generations down, you would be plain second cousins — no removals — because you would share great-grandparents and sit in the same generation. That single difference is the one that trips up nearly everyone, and it's the whole reason the “removed” idea exists.
How do I figure out a relationship fast?
Find the closest ancestor you both descend from, count the generations down to each person, then apply the two rules: the shorter path sets the cousin number, and the difference between the paths is how many times you're removed. Or enter both people in a calculator and skip the arithmetic entirely.
Our family relationship calculator does exactly that in your browser and draws a chart you can print or share. And once you're mapping real people rather than hypotheticals, AncestorIQ can build your family tree as you chat — every relationship named automatically as the tree grows.
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