Kinship Degree & Relationship Calculator | Second Cousins, Cousin's Children, Great-Uncles: What Degree? Names, Legal Relatives, Marriage, Inheritance & Bereavement Leave (with Family Tree, Free)
The Kinship Degree & Relationship Calculator is a free tool that tells you what degree (shintō, 親等) a person is and what to call them, simply by tracing father, mother, brothers, sisters, sons, daughters, husband and wife from yourself. It shows names and readings for second cousins (hatoko, 6th degree), cousins' children and parents' cousins (itoko-chigai, 5th degree), great-uncles and great-aunts (4th degree), the difference between 伯父 and 叔父, brother-in-law, sister-in-law, daughter-in-law, son-in-law, father- and mother-in-law, and aimuko, aiyome and aiyake. It separates lineal and collateral, ascendant and descendant, and blood relatives and relatives by marriage, and judges whether the person is a relative under Article 725 of the Civil Code (blood relatives within the 6th degree, spouses, and relatives by marriage within the 3rd degree). It also shows whether you can marry (Civil Code Arts. 734 and 735), the duty of support (Art. 877), the order of statutory heirs and substitutional inheritance, bereavement leave days for national civil servants (National Personnel Authority rules), and a guide to the range for mourning-period cards. The people you traced are drawn in a family tree, and the way degrees are counted (generations up to the common ancestor plus generations down) is explained as a formula. A quick-reference table lets you look up relations by name.
Trace from yourself
Tap "Father", "Elder Brother", "Son" and so on in order, starting from yourself. For example, a second cousin (hatoko) is Father → Father → Elder Brother → Son → Son (the grandson of your grandfather's elder brother).
Parents
Siblings
Child
Spouse
Father's Father's Elder Brother's Son's Son is
Second cousin, male (hatoko, 再従兄弟)
hatoko
Also called / written: matatoko, futaitoko, 再従兄弟 (second cousin)
- How degrees are counted
- From Me, go up 3 generation(s) to the common ancestor (Me's great-grandparents), then down 3 generation(s) to the other person: 3 + 3 = degree 6. For collateral relatives, add "generations up + generations down".
- Generation
- Same generation as you(collateral)
- Can they marry?
- ○Yes. There is no marriage restriction for collateral blood relatives of the fourth degree or beyond (outside the scope of Civil Code Art. 734).
- Duty of support
- There is no duty of support.
- Inheritance
- Not a statutory heir (property can still be bequeathed by will). A relative who, without compensation, provided nursing care or similar help and made a special contribution can claim a "special contribution payment" (tokubetsu kiyo-ryō) (Civil Code Art. 1050).
- Bereavement leave days (kibiki)
- Not covered by the national civil servants' bereavement leave rules (National Personnel Authority Rule 15-14). Companies often do not cover this either, and taking paid leave to attend the funeral is the usual practice.
- Mourning-period cards (mochū hagaki)
- Mourning-period cards (mochū hagaki) are not normally sent.
Family tree
The people you traced are laid out by generation (older at the top). The number under each box is that person's degree from you.
━ Parent–child┏━┓ Siblings＝ Married couple□ Person being looked up
Quick reference by degree (search by name)
Commonly looked-up relatives are listed by degree. Tap one to load it into the calculator above. You can also search by name or hiragana, such as "hatoko", "itoko-chigai", "giri no ani", or "aimuko".
Spouse
Degree 1
Degree 2
Degree 3
Degree 4
Degree 5
Degree 6
Degree 7 or more
Not a relative
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About Kinship Degree & Relationship Calculator | Second Cousins, Cousin's Children, Great-Uncles: What Degree? Names, Legal Relatives, Marriage, Inheritance & Bereavement Leave (with Family Tree, Free)
The Kinship Degree & Relationship Calculator tells you what degree a person is and what to call them: starting from yourself, simply tap "Father", "Mother", "Elder Brother", "Elder Sister", "Younger Brother", "Younger Sister", "Son", "Daughter", "Husband" and "Wife" in order. For lineal relatives the degree is the number of generations; for collateral relatives it is "generations up to the common ancestor + generations down from there". For example, a second cousin (hatoko, a grandfather's sibling's grandchild) means going up 3 generations to the great-grandparents and down 3, so it is 6th degree; a cousin's child or a parent's cousin (itoko-chigai) is 5th degree; and a great-uncle or great-aunt is 4th degree. Blood relatives of a spouse (father-in-law, brother-in-law and so on) and spouses of blood relatives (elder brother's wife, daughter-in-law, son-in-law and so on) are relatives by marriage and are counted the same way; a spouse itself has no degree. The result shows the name and reading, lineal or collateral, ascendant or descendant, blood relative or relative by marriage, and whether the person is a relative under Article 725 of the Civil Code (blood relatives within the 6th degree, spouses, and relatives by marriage within the 3rd degree). It also lists whether you can marry (Civil Code Arts. 734 and 735), the duty of support (Art. 877), the order of statutory heirs and substitutional inheritance, the bereavement leave days for national civil servants (National Personnel Authority Rule 15-14), and a guide to the range for mourning-period cards. The path you traced is drawn as a family tree, and there is a quick-reference table of degrees that you can search by name.
How to use Kinship Degree & Relationship Calculator | Second Cousins, Cousin's Children, Great-Uncles: What Degree? Names, Legal Relatives, Marriage, Inheritance & Bereavement Leave (with Family Tree, Free)
- 1In "Trace from yourself", tap Father, Mother, Elder Brother, Elder Sister, Younger Brother, Younger Sister, Son, Daughter, Husband or Wife in order until you reach the person you want to look up (example: a second cousin is Father → Father → Elder Brother → Son → Son)
- 2Check the large name and degree, whether the person is a blood relative or a relative by marriage, and whether they count as a relative under the Civil Code
- 3Use the formula under "How degrees are counted" and the family tree to see which ancestor the count passed through
- 4Check the rows for marriage, duty of support, inheritance, bereavement leave days and mourning-period cards for whatever you want to know
- 5If you already know the name, look it up in the quick-reference table below, such as "hatoko" or "giri no ani", and tap it. "Copy URL for this relation" lets you share it with family
Great for
- I want to know what degree a second cousin (hatoko), third cousin (mi-itoko) or itoko-chigai is
- I want to know what to call a cousin's child or a parent's cousin
- I want to check the name for a grandfather's younger brother (great-uncle) or a nephew's child (grand-nephew)
- I want to know which character to write for uncle or aunt: 伯 or 叔
- I want to know what degree of relative by marriage a brother-in-law, an elder brother's wife or a spouse's sibling is
- I want to check whether someone falls under "relatives within the 3rd degree" or "blood relatives within the 6th degree" on a form
- I want to check whether a relation is covered by bereavement leave or the range for mourning-period cards
- I want to know whether I can marry a cousin or a spouse's sibling, or whether they would be an heir
Good to know
- Degrees are counted as in Article 726 of the Civil Code. For lineal relatives it is the number of generations; for collateral relatives it is the sum of the generations up to the common ancestor and the generations down from there. A spouse has no degree, and relatives by marriage are counted by placing the spouse in your own position.
- Relatives under the Civil Code (Art. 725) are blood relatives within the 6th degree, spouses, and relatives by marriage within the 3rd degree. Blood relatives of the 7th degree or beyond (such as a second cousin's child), relatives by marriage of the 4th degree or beyond, and people such as the husband of your wife's sister (aimuko) or the parents of your elder brother's wife are not legal relatives.
- Parents and children are counted as biological, and siblings as having the same two parents. Paths that return to the same person, such as "Father's Son" (you or a brother) or "Elder Brother's Father" (the same person as your father), cannot be chosen, and the reason is shown. Adopted children and half-siblings are not included (an adopted child becomes a blood relative equal to a biological child from the date of adoption).
- 伯 (haku) is used for a sibling older than your parent and 叔 (shuku) for a younger one (a father's elder brother is 伯父, a mother's younger sister is 叔母). A cousin older than you is written 従兄 / 従姉, and a younger one 従弟 / 従妹.
- Marriage restrictions are judged only by Article 734 of the Civil Code (lineal blood relatives and collateral blood relatives within the 3rd degree) and Article 735 (lineal relatives by marriage, even after the relationship has ended). Restrictions arising from adoptive relationships (Art. 736) are not included.
- Inheritance shows the spouse, children (first rank), lineal ascendants (second rank), siblings (third rank), and substitutional inheritance when a child or sibling died first. Actual shares and changes due to wills or renunciation are not calculated.
- Bereavement leave days follow the example for national civil servants (National Personnel Authority Rule 15-14, Appendix 2). A company's bereavement leave (kibiki) is set by its work rules, and both the days and the scope differ by company. The range for mourning-period cards (spouse and up to the 2nd degree) is a general guide.
- The path you traced is saved only in this device's browser and is never sent to a server.
Questions this tool answers
Use Kinship Degree & Relationship Calculator | Second Cousins, Cousin's Children, Great-Uncles: What Degree? Names, Legal Relatives, Marriage, Inheritance & Bereavement Leave (with Family Tree, Free) for searches like these:
- I want to know what degree a second cousin is
- I want to know what to call a cousin's child
- I want to know how degrees of kinship are counted
- I want to know what degree a brother-in-law or sister-in-law is
- I want to know who falls within the 3rd or 6th degree
- I want to know whether I can marry a cousin
- I want to know up to which degree bereavement leave is allowed
- I want to know whether aimuko and aiyome are relatives
FAQ
- What degree is a second cousin (hatoko)?
- A second cousin is a 6th-degree collateral blood relative. A hatoko (also called mata-itoko) is a grandchild of your grandparent's sibling, and your parents are cousins of each other. You go up 3 generations to the common ancestor, your great-grandparents, and down 3, so 3 + 3 = 6th degree. Since this is a blood relative within the 6th degree, a second cousin counts as a relative under the Civil Code. A second cousin's child is 7th degree and is not a relative.
- What do you call a cousin's child or a parent's cousin?
- Both are called itoko-chigai (also written 従兄弟違い) and are 5th-degree collateral blood relatives. A cousin's child can also be written 従甥 (jūsei) or 従姪 (jūtetsu), and a parent's cousin 従伯叔父 (itoko-oji) or 従伯叔母 (itoko-oba). Your own children and your cousin's children are second cousins (hatoko) to each other.
- How are degrees of kinship counted?
- For lineal relatives (parents, grandparents, children, grandchildren), the number of generations is the degree: parents and children are 1st degree, and grandparents and grandchildren are 2nd degree. For collateral relatives (siblings, uncles and aunts, cousins and so on), add the number of generations up to the common ancestor and the number of generations down from there to the other person. A cousin is 4th degree, because you go up 2 to the grandparents and down 2. This tool shows the formula under "How degrees are counted" in the result.
- What degree is a brother-in-law (a spouse's brother or an elder sister's husband)?
- Both are 2nd-degree collateral relatives by marriage. A spouse's brother is a blood relative of your spouse, and an elder sister's husband is the spouse of a blood relative. Both are relatives by marriage and are counted at the same 2nd degree as the sibling concerned. Since they are within the 3rd degree of relatives by marriage they count as relatives under the Civil Code, but they are not statutory heirs.
- Can I marry a cousin?
- Yes. Article 734 of the Civil Code prohibits marriage only with lineal blood relatives and collateral blood relatives within the 3rd degree (siblings, uncles and aunts, nephews and nieces). A cousin is a 4th-degree collateral blood relative, so there is no legal restriction. You cannot marry a lineal relative by marriage (such as a spouse's parent or a child's spouse) even after the relationship by marriage ends through divorce or similar (Art. 735).
- Who is included in the range of relatives (within the 3rd degree, within the 6th degree)?
- Relatives under the Civil Code are blood relatives within the 6th degree, spouses, and relatives by marriage within the 3rd degree. Among blood relatives this goes up to second cousins (6th degree); among relatives by marriage it covers a spouse's uncles, aunts, nephews and nieces, and the spouses of your own uncles and aunts (3rd degree). For a form that says "relatives within the 3rd degree", it covers blood relatives and relatives by marriage up to the 3rd degree (great-grandparents, uncles and aunts, nephews and nieces, great-grandchildren and so on) and the spouse.
- Are aimuko and aiyome relatives?
- In everyday family dealings they are sometimes called "in-law siblings", but they are not relatives under the Civil Code. Aimuko are the husbands of sisters, and aiyome are the wives of brothers. Because each is the spouse of a blood relative of your spouse (a relative by marriage), they fall outside the range of relatives. The parents of a couple's two sides (aiyake) are likewise not relatives.
- Up to which degree can I take bereavement leave?
- It is set by the company's work rules, and many cover up to the 2nd or 3rd degree. For national civil servants (National Personnel Authority Rule 15-14), it is 7 days for a spouse or parent, 5 days for a child, 3 days for a grandparent or sibling, and 1 day for a grandchild or uncle or aunt; 3 days for a spouse's parent, and 1 day for a spouse's sibling or a sibling's spouse (longer if you lived on shared finances). Cousins are not covered.
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