Understanding fixed heirs, residuary heirs, and how the shares are calculated.
Published August 29, 2026 · Reviewed by the Ihsabha Editorial Team
Islamic inheritance law — known as mirath or fara'id — is one of the most precisely detailed areas of Islamic jurisprudence, with share ratios set out directly in the Quran. Because the calculation depends on exactly which relatives survive the deceased, it can feel complex at first. Here's how the system actually works.
These heirs receive a specific fraction of the estate defined by the Quran — such as 1/2, 1/4, 1/8, 1/3, 2/3, or 1/6 — depending on their relationship to the deceased and which other relatives are also alive. Common examples:
After fixed shares are distributed, whatever remains of the estate goes to residuary heirs — typically sons, and daughters when inheriting alongside sons. The standard ratio is 2 shares for a son to every 1 share for a daughter in this category.
The presence or absence of certain relatives changes the shares of others — for example, a mother's share shifts from 1/3 to 1/6 if the deceased has children or multiple siblings. This interdependence is exactly why manual calculation is error-prone for anything beyond the simplest family structures.
A man passes away leaving a wife, one son, and one daughter, with no surviving parents. The wife receives 1/8 (since there are children). The remaining 7/8 is split between the son and daughter at a 2:1 ratio — the son receiving 2/3 of that remainder and the daughter 1/3.
Get the exact breakdown for your family. Ihsabha's Islamic Inheritance Calculator takes your specific list of surviving heirs and instantly returns each person's correct share — no manual fiqh calculation required.
1/8 of the estate if there are children, or 1/4 if there are none — divided equally among multiple wives.
Yes — a single daughter with no sons receives 1/2; two or more daughters with no sons share 2/3; alongside sons, daughters inherit as residuary heirs at a 1:2 ratio to sons.
Fixed heirs receive an exact Quranic fraction regardless of the estate size; residuary heirs split whatever remains afterward.
Inheritance calculations can involve additional complexities — such as bequests (wasiyyah, capped at one-third of the estate), debts of the deceased, or unusual family structures involving grandparents and siblings together. For estate matters of any significant value, consulting a qualified scholar or Islamic inheritance specialist alongside the calculator is strongly recommended.