Cousin Relationship Calculator
Cousin relationship calculator — work out first cousin once removed, second cousin twice removed and more, from a family path or from each person's distance to the common ancestor. Shows the degree-and-removal diagram, in English, Chinese (堂/表) and Malay. Runs in your browser.
Cousin Relationship Calculator
Example: your father's brother's son is father → brother → son (a first cousin, 堂 in Chinese). For a first cousin the path decides 堂 or 表, and a path that can mean more than one person, such as "father → son", lists each.
How to Use the Cousin Relationship Calculator
Choose a mode
"From a relationship" lets you build the family path step by step. "From the common ancestor" lets you enter how many generations each person is from the ancestor you share.
Enter the family link
Build a path like "father → brother → son", or type the two generation distances — a grandparent is 2, a great-grandparent is 3.
Read the answer
You get the exact term — first cousin, second cousin once removed — with a common-ancestor diagram and the degree and removal worked out step by step.
Switch language
See the relationship in English, Chinese (堂 same-surname vs 表 other line) or Malay (sepupu, dua pupu, tiga pupu). For a first cousin built from a path, the calculator reads 堂 or 表 from the path itself. From two distances there is no path to read, and for more distant cousins the dictionary gives no definition, so it shows both forms.
"First Cousin Once Removed", Finally Explained
Few family terms cause as much confusion as "first cousin once removed". People reach for it whenever a cousin feels a bit distant, and just as often confuse it with "second cousin". The two are genuinely different, and the difference comes down to two simple numbers measured against the common ancestor that two people share. This calculator works those numbers out for you — either from a family path you build, or directly from the generation distances — and shows the result in English, Chinese and Malay.
Degree and removal, in plain terms
The cousin degree — first, second, third — is one less than the number of generations from the nearer of the two people up to the shared ancestor. Share a grandparent (two generations up) and you are first cousins; share a great-grandparent (three up) and you are second cousins. The removal is simply the difference between how far each person stands from that ancestor. If you are two generations from your common ancestor and your relative is three, you are "once removed" — one generation out of step. So your parent's first cousin, and your first cousin's child, are both your first cousin once removed: same degree, one generation apart. A second cousin, by contrast, is in your own generation and shares a great-grandparent with you.
Degree counts how far back the shared ancestor is; removal counts the generation gap between the two of you. Two numbers, and the mystery is gone.
The same idea across three languages
English describes cousins with degree and removal; other languages frame the same family fact differently. Chinese distinguishes whether the shared ancestor is on the paternal, same-surname line — 堂 (tóng) — or any other line, including the maternal side — 表 (biǎo). Taiwan’s Ministry of Education dictionary defines 堂兄弟 as the sons of one’s father’s brothers and 表兄弟 as the sons of one’s father’s sisters and mother’s brothers and sisters. Those definitions cover first cousins. So when you build a path to a first cousin, the calculator reads the line from it: 堂 when every link between you is male, 表 as soon as the line passes through a woman. For a second cousin, or a cousin who is removed, it shows both forms and says which one the same rule would give, marked as an extension of the definition rather than part of it. With only two distances to go on there is no path to read, so it shows both forms unless you choose the line. Malay counts degrees but not removals: Kamus Dewan Perdana, the Malay national dictionary, defines sepupu as the child of an uncle or aunt, dua pupu as two people whose parents are first cousins and tiga pupu as two people whose great-grandparents were siblings. Neither it nor the Indonesian KBBI records a word for a cousin who is “removed”, so the Malay line shows a dash there rather than an invented form. Switch the output language to see the same two people named in each tradition. Everything is computed in your browser with a small built-in engine — nothing about your family is sent anywhere.
Chinese marks which line the ancestor came down
Your cousin degree is one less than the generations from the nearer of you to the shared ancestor.
"Removed" counts a generation gap, not emotional or family distance.
First cousins share a grandparent; second cousins, a great-grandparent.
Your parent's first cousin is your first cousin once removed.
A second cousin is in your generation and shares a great-grandparent.
Removal is symmetric — it doesn't matter which cousin is older.
Chinese marks the ancestor's line: 堂 (same surname) vs 表 (other line).
Malay names cousin degrees: sepupu, dua pupu, tiga pupu (Kamus Dewan Perdana).
If one distance is zero it's a direct line, not a cousin relationship.
This calculator runs in your browser — nothing is uploaded.
Frequently Asked Questions
- It is a first cousin who is one generation apart from you. Your parent's first cousin, and your first cousin's child, are both your first cousin once removed. "Removed" counts the generation gap between you, not how distant the family feels.
- A second cousin is in your own generation and shares a great-grandparent with you. A first cousin once removed shares a grandparent through one of you and sits one generation apart. The diagram in the tool shows the difference clearly.
- Degree = (the shorter distance to the common ancestor) − 1. Removal = the difference between the two distances. For example, distances of 2 and 3 give degree 1 (first cousin) and removal 1 (once removed). The calculator does this for you.
- "From a relationship" lets you build the family path (father → brother → son). "From the common ancestor" lets you type how many generations each person is from the ancestor you share. Both give the same kind of answer with a diagram.
- Chinese distinguishes cousins on the paternal, same-surname line (堂) from those on any other line, including the maternal side (表). Taiwan's Ministry of Education dictionary defines 堂兄弟 as the sons of your father's brothers. That definition covers first cousins. For a first cousin built from a path, the tool reads the line from it: 堂 if every link between you is male, 表 otherwise. For more distant cousins it shows both forms and notes which one the same rule would give, as an extension rather than a definition. With only two distances there is no path to read, so it shows both unless you choose.
- Kamus Dewan Perdana, the Malay national dictionary, gives "sepupu" for a first cousin, "dua pupu" for a second cousin and "tiga pupu" for a third. It records no word for a cousin once or twice "removed", and neither does the Indonesian KBBI, so for those the calculator shows a dash in the Malay line instead of inventing a form.
- Yes. If the numbers describe a parent and child, a grandparent, siblings, or an aunt/uncle and niece/nephew, the tool says so rather than forcing a cousin label — those are direct-line or aunt/uncle relationships, not cousins. And when a path can name more than one person, it lists each: "father → son" is you if you are male, or your brother, and "son → mother" is you if you are female, or your partner, who is related by marriage rather than by blood.
- No. The removal is the difference between the two generation distances, so it is the same whichever person you start from. "First cousin once removed" describes the pair, in both directions.
- No. Every calculation runs in your browser on a small built-in engine — nothing about your family is uploaded to a server or third party. It works offline once the page has loaded.
- Completely free, with no account, sign-up, or usage limit. It runs entirely in your browser and collects no data. Use it as much as you like.
Method & sources
How it computes
Build a path from yourself (father, mother, brother, sister, son, daughter) or enter how many generations each person stands from the shared ancestor. Both reduce to two numbers: the degree is the smaller distance minus one, and the removal is the difference (three and four generations give second cousins once removed). For a first cousin the path also decides the Chinese 堂/表 line, and a path that can name more than one person, such as father → son, lists each reading.
What this tool implements
- The cousin rule is the standard genealogical one computed from the common ancestor: degree = smaller generation distance − 1; removal = difference between the two distances. It is definitional, so it gives the same answer in every tradition
- Chinese labelling follows the 堂／表 distinction as Taiwan's Ministry of Education dictionary defines it: 堂兄弟 are the sons of one's father's brothers, 表兄弟 the sons of one's father's sisters and mother's brothers and sisters. Those entries define first cousins only. For a first cousin reached by a path the tool prints 堂 only when every link between the two people is male. For other cousins, and from two typed distances, which carry no line, it shows both forms and marks the father's-line reading as an extension of the definition
- Beyond first cousins no single everyday Chinese term is used here: Chinese uses 從／再從 for those degrees, so the tool prints 堂亲 or 表亲 with the English degree in brackets rather than invent a term — a gap in labelling, not in arithmetic
- Malay labels follow Kamus Dewan Perdana: sepupu for a first cousin, dua pupu for a second and tiga pupu for a third. Neither it nor the Indonesian KBBI records a word for a removed cousin or a fourth cousin, so the tool prints a dash there rather than invent one
- Aunt/uncle and niece/nephew pairs are named from the generation gap: the older side takes one "great-" fewer than the gap, and the younger side is grand-niece or grand-nephew at a gap of two, with one "great-" more for each further generation
- A path is read assuming full siblings. A step that can lead back to you or your own line (father → son, brother → brother) or to a partner (son → mother) is answered with every relative it can name; a relation by marriage is named as one, never given a cousin degree
Sources
- Fêng Han-yi (Fêng Han-chi). The Chinese Kinship System. Harvard Journal of Asiatic Studies 1937;2(2):141-275; reissued Cambridge, MA: Harvard University Press for the Harvard-Yenching Institute, 1948 — the paternal same-surname (堂) versus other-line (表) distinction the Chinese labels encode.
- Ministry of Education (Taiwan). 重編國語辭典修訂本 — entries 堂兄弟 (「用以稱伯叔的兒子」) and 表兄弟 (「用以稱姑母、舅父、姨母的兒子」), read 7 October 2026. https://dict.revised.moe.edu.tw/
- Arnold JS. Kinship: It's All Relative. Enlarged 2nd ed. Baltimore: Genealogical Publishing Co.; 2012 — cousin degrees and the 'once/twice removed' nomenclature.
- Kamus Dewan Perdana (Dewan Bahasa dan Pustaka, 2020), public search at https://kamus.dbp.gov.my/ — entries saudara pupu (sepupu), dua pupu and tiga pupu (read 2 October 2026).
What can make this go out of date
- Nothing is fetched at runtime. What could date this page is terminology rather than arithmetic — kinship vocabulary varies by region and dialect, and the Chinese labels are the standard Mandarin forms.
Abridged — the full review record for this tool runs longer than the list above.
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