Mīrāth is the Islamic law of inheritance: the rules by which a person's wealth passes to their relatives after death. It is also called ʿilm al-farāʾiḍ — the science of the fixed shares — because its heart is a set of precise fractions that the Qurʾan assigns to named relatives. The Prophet ﷺ called it half of all knowledge, and the early community treated a mistake in it as a serious matter, since an error quietly takes from one heir what belongs to another.
Order of distribution
Before any heir inherits, four claims are met from the estate in order:
- Funeral expenses a dignified burial.
- Debts everything owed to people and to God.
- Bequest (waṣiyya) up to one third of what remains, to non-heirs.
- The fixed shares (farāʾiḍ) the rest is divided among the heirs by the rules below.
The calculator's “Debts, funeral & bequest” section nets the estate down to the amount that is actually divided, capping the bequest at one third.
The fixed shares — al-furūḍ
Allah names the shares of close relatives in the Qurʾan (chiefly 4:11, 4:12 and 4:176). Each fraction is conditional on who else survives.
- 1/2 النصف
- Husband when there is no child
- A sole daughter
- A sole son's daughter
- A sole full sister
- A sole paternal sister
- 1/4 الربع
- Husband with a child
- Wife (or wives, shared) with no child
- 1/8 الثمن
- Wife (or wives, shared) with a child
- 2/3 الثلثان
- Two or more daughters
- Two or more son's daughters
- Two or more full sisters
- Two or more paternal sisters
- 1/3 الثلث
- Mother no child and fewer than two siblings
- Two or more maternal siblings (shared equally)
- 1/6 السدس
- Father with a child
- Mother with a child or two or more siblings
- Grandfather with a child
- Grandmother
- A sole maternal sibling
- Son's daughter completing a daughter's ⅔
- Paternal sister completing a full sister's ⅔
Residuary heirs — al-ʿaṣaba
After the fixed shares are paid, whatever remains goes to the residuary heirs (ʿaṣaba) — the agnatic relatives, nearest first: the son, then the son's son, the father, the grandfather, then the brothers and their lines. Where a male and female of the same rank inherit together (a son and a daughter, a brother and a sister), the male takes the share of two females (2:1).
A daughter or a sister normally takes a fixed share, but becomes a residuary when she inherits alongside her brother, or — for a full or paternal sister — alongside a daughter.
Blocking — al-ḥajb
A nearer heir can exclude a more distant one, either completely (ḥajb ḥirmān) or by reducing their share (ḥajb nuqṣān). For example: a son blocks the son's son and all the siblings; the father blocks the brothers; the mother is reduced from ⅓ to ⅙ when a child or two or more siblings survive.
The calculator shows blocked heirs greyed out with the reason they were excluded, so nothing is hidden.
ʿAwl & radd
ʿAwl (over-subscription): sometimes the fixed shares add up to more than the whole estate — for example a husband (½) with two full sisters (⅔). The base of the problem is raised so the shares fit, and everyone is reduced in proportion.
| Heir | Named share | After ʿawl |
|---|---|---|
| Husband | 1/2 | 3/7 |
| Full sister × 2 | 2/3 | 4/7 |
Radd (return of surplus): the opposite — the fixed shares fall short and there is no residuary heir to take the remainder. The surplus is returned to the fixed-share heirs in proportion, with one exception: the spouse does not share in the radd. Only when a spouse is the sole heir does the later Ḥanafī fatwa return the surplus to them; the other schools send it to the public treasury.
The four schools — al-madhāhib
For the overwhelming majority of families, the four Sunni schools — Ḥanafī, Mālikī, Shāfiʿī and Ḥanbalī — give exactly the same result. Their numbers differ in three places: when a grandfather inherits alongside full or paternal siblings (al-Jadd wa al-Ikhwa); when a surplus remains and the only heir is a husband or wife — the later Ḥanafī fatwa returns it to the spouse, while the other three schools send it to the bayt al-māl; and with distant kin (dhawū al-arḥām), whom the Ḥanafīs divide by nearness of kinship and the others by tanzīl, each relative standing in for the heir through whom they reach the deceased.
The Ḥanafī school treats the grandfather as a father, so he excludes the siblings entirely. The Mālikī, Shāfiʿī and Ḥanbalī schools let him share with them (muqāsama), taking whichever is best for him: a share alongside them as a brother, one third of the remainder, or one sixth of the whole estate. The Mālikī and Shāfiʿī schools also apply al-Mushtaraka, letting full brothers share the maternal siblings' third. The calculator computes all four and tells you when they differ.
Topics in depth
Each rule has its own page, with live examples and the points where the four Sunni schools part ways.
- ʿAwl (proportional reduction): when the shares exceed the estate How the base of a case is raised so that every fixed-share heir gives up the same proportion, a method all four Sunni schools accept.
- Radd (return): giving the surplus back to the heirs What happens when the fixed shares leave something over and no residuary heir is there to take it, and why the spouse is left out.
- Ḥajb (blocking): how one heir excludes or reduces another Which relatives shut others out entirely, which only shrink another's share, and the six heirs who can never be excluded.
- ʿAṣaba: the residuary heirs Who takes what is left once the fixed shares are paid, in what order, and how a daughter or a sister becomes a residuary.
- Aṣl and taṣḥīḥ: the base of a case and its correction How a case is set on one common denominator, and how that base is multiplied so that every heir receives a whole number of parts.
- al-ʿUmariyyatān: the mother's third of the remainder Two cases decided by ʿUmar ibn al-Khaṭṭāb, in which the mother takes a third of what the spouse leaves rather than a third of the whole.
- al-Mushtaraka: full brothers sharing the uterine siblings' third A case in which the full brothers would receive nothing, and the schools split over whether they may join their uterine siblings' third.
- al-Akdariyya: the grandfather and the sister The one case in which Zayd ibn Thābit gave a full or paternal sister a fixed share beside the grandfather, and then pooled the two.
- The grandfather with brothers and sisters Whether the paternal grandfather excludes the deceased's siblings or shares with them, and the options Zayd gave him when he shares.
- Muʿādda: counting paternal siblings against the grandfather How full siblings count their paternal half-siblings to reduce the grandfather's portion, then take that portion back for themselves.
- Dhawū al-arḥām: relatives through the female line Who the distant kindred are, when they inherit, and the two methods the schools use to divide between them.
- Before the shares: funeral costs, debts and bequests What comes out of the estate before the heirs divide it, in what order, and the one-third limit on bequests.
- Debts to God: unpaid zakat, kaffārah and ḥajj Is unpaid zakat, kaffārah or ḥajj taken from the estate before the heirs divide it? Each Sunni school's rule, with its source.
- Bequests: the one-third limit and the heirs' consent A bequest above a third or to an heir: what the heirs' consent does, when it counts, and how several bequests share a third. Each school's view.
- Impediments: who cannot inherit Killing the deceased, a difference of religion and slavery bar an heir in all four Sunni schools. Where the schools differ on which killing bars.
- Gifts made in the final illness (maraḍ al-mawt) A gift handed over in the illness that ends in death counts against the one-third limit, like a bequest. What the schools say, with sources.
- Obligatory bequest (waṣiyya wājiba) by country Some countries' laws give grandchildren whose parent died first a share of up to a third. What each statute says, with links to the texts used.
Calculators and tools
Beyond the main calculator: successive deaths, real assets, national statutes and the three cases where an heir is uncertain.
- Munasakha calculator When an heir dies before the estate is divided: the second estate worked from the first, with exact shares.
- Divide assets Split a house, land or cash by each heir’s share, settle the difference in money, and convert marla, kanal or bigha.
- Law by country How the inheritance statutes of 11 countries change the classical shares, with articles cited.
- Missing heir (mafqūd) The share held for an heir who has vanished, in each school, and what the others are paid now.
- Unborn child (ḥaml) The share held while the widow is pregnant, and what changes at birth.
- Intersex heir (khunthā) The four schools’ methods for an heir whose sex is unresolved.