Faraidh — the Islamic Law of Inheritance

What faraidh is

Faraidh (also written fara'id or faraid, from faridah, "an obligatory portion") is the Islamic law of inheritance — the set of rules that determine who inherits from a deceased Muslim, and exactly how much each heir receives. It is widely regarded by scholars as one of the most detailed and precisely specified areas of fiqh, for a simple reason: in most areas of Islamic law, the Quran lays down broad principles and leaves scholars to derive detailed rulings through reasoning (ijtihad) applied to the Quran and Sunnah. Inheritance is different. Here, the Quran itself states the actual shares — halves, thirds, quarters, sixths, eighths — in plain arithmetic terms, for specific classes of relatives.

The core of faraidh comes from two consecutive ayat near the start of Surah An-Nisa, which open by fixing the shares of children and parents:

The very next ayah continues in the same explicit style, fixing the shares of a surviving spouse — a half or a quarter for a husband, a quarter or an eighth for a wife, depending on whether the deceased left children — and the shares of siblings inheriting from someone who left no parent or child (a case known as kalalah):

Immediately after setting out the shares, the Quran frames them in unusually forceful language for a legal matter — as fixed boundaries set by Allah Himself, with an explicit warning attached to transgressing them:

Very few rulings in the Quran are followed by a promise of Paradise for observing them and a warning of the Fire for transgressing them, in the very next two ayat. Scholars point to exactly this — the explicit numbers in 4:11–12, immediately sealed by the "limits of Allah" language in 4:13–14 — as the reason inheritance is treated as uniquely non-negotiable within fiqh: a matter for careful, precise calculation according to the text, not personal preference, family pressure, or a testator's wish to freely reassign shares by will.

The fractions are calculated on the net estate, not on everything the deceased left behind. Quran 4:11 and 4:12 both repeat the same clause — the shares apply "after any bequest he may have made or debt" — and the jurists spell out the sequence: first the funeral and burial costs, then all debts (including an unpaid mahr and zakat still owed), then any bequest up to the one-third cap, and only then the faraidh division. Notably, the Prophet ﷺ put debts ahead of the bequest even though the Quran's wording mentions the bequest first: "The Prophet judged with the debt before the will, and you people recite the will before the debt" (Jami' at-Tirmidhi 2122 — its chain contains al-Harith al-A'war and is graded weak, but at-Tirmidhi himself records that the people of knowledge act upon it, and the ruling is agreed upon). Skipping a step — dividing shares while debts sit unpaid — invalidates the arithmetic that follows.

Being named in Quran 4:11–12 is not the end of the matter — classical fiqh recognises barriers (mawani' al-irth) that strip an otherwise-entitled heir of their share entirely. Two matter in practice today. First, homicide: one who kills the person they would have inherited from is barred, so that inheritance can never become a motive — "If one of them killed the other deliberately, then he or she inherits nothing from the blood money or wealth" (Sunan Ibn Majah 2736, hasan). The schools differ at the edges: Hanafis and Shafi'is bar even some non-deliberate killing, while Malikis bar only intentional killing. Second, difference of religion: "A Muslim cannot be the heir of a disbeliever, nor can a disbeliever be the heir of a Muslim" (Sahih al-Bukhari 6764 · Sahih Muslim 1614). A barred heir is treated as if absent, and their share flows on — one more reason a real estate needs a scholar's review.

Without attempting to calculate any specific case, the overall architecture of faraidh has two layers of heirs:

That hadith is the bridge between the two layers: pay the fixed shares the Quran names first, then hand anything left over to the nearest male relative in the paternal line. It sounds simple as a two-step rule. In practice it is not, because which fraction applies to which heir changes depending on exactly who else is alive. A few examples of how much the answer moves:

• A wife's share is 1/8 if her husband left children, but 1/4 if he did not.
• A mother's share is 1/6 if the deceased left children or two or more siblings, but 1/3 otherwise.
• A single daughter's share is 1/2 if she has no brother, but if she has a brother she stops being a fixed-share heir at all and instead shares the residue with him as 'asabah, at a 2:1 split in the male's favor (his share is double hers).
• Full or paternal siblings can be entitled to a share, a reduced share, or nothing at all, depending on who else survives — a father or a son blocks them entirely, but a daughter alone does not.

Multiply this by every possible combination of spouse, parents, children, and siblings who might survive a given person, and the number of distinct scenarios becomes very large very quickly — some configurations also require a corrective step (called 'awl or radd) when the named fractions add up to more or less than the whole estate. This is genuinely specialist arithmetic, not a simple lookup table — which is why the simulator below only computes the well-defined common cases, and says so plainly whenever a combination falls outside them rather than guessing.

Below is a simulator for the well-defined, common family structures — a surviving spouse, children, and/or parents, with a childless-decedent case covering siblings. It is built to refuse a guess rather than give a wrong one: a number of real, frequent situations fall outside what it computes (explained below the tool), and for those it says so plainly instead of estimating.

Faraidh only governs what's left after death. That naturally raises the question: can someone give their wealth away beforehand, and sidestep the fixed shares entirely? Islamic law draws a clear line between three different situations, and treats each differently.

Note that this hadith is itself the reason the 1/3 cap extends to deathbed gifts, not only formal written bequests: Sa'd was asking the Prophet ﷺ about giving his wealth away in charity, while gravely ill — the exact "marad al-mawt" situation — and the Prophet ﷺ capped it at a third all the same.

The reason the cap exists at all — rather than leaving the whole estate to a will — is stated directly in the Sunnah too: a bequest cannot be made to someone who is already a faraidh heir, on top of their fixed share, without every other heir's consent. This protects the very shares Quran 4:11–12 fixes from being quietly reassigned by a will.