Islamic inheritance calculator
Enter the estate and who survives. The calculator takes out funeral costs, debts and any bequest, then divides the rest by the shares set in the Qur'an (4:11, 4:12 and 4:176), showing each heir's fraction, amount and the reason for it.
Covers a husband or up to four wives, sons, daughters, father, mother, and full brothers and sisters. Grandparents, grandchildren, half-siblings and other relatives are not included yet. Estates are legal matters too: use this to understand the shares, and confirm with a scholar and a will specialist.
How the shares work
Islamic inheritance gives some relatives a fixed share named in the Qur'an, and gives what is left to the closest male relatives and those who inherit with them. A husband takes half, or a quarter if there are children. Wives share a quarter, or an eighth if there are children. A single daughter with no son takes half; two or more share two thirds. A mother takes a third, or a sixth if there are children or two or more siblings. A father takes a sixth if there are children, and the rest otherwise.
Sons and daughters together
When there is a son, the children inherit what is left after the fixed shares, and a son takes twice a daughter's share. Full brothers and sisters inherit only when there is no son and no father; with daughters but no son or father, full sisters take what is left.
When the shares do not fit exactly
If the fixed shares add up to more than the estate, each is reduced in proportion. This is called awl. If they add up to less and nobody is left to take the remainder, it is returned to the fixed-share heirs in proportion, except the spouse; this is called radd. If only a spouse survives, schools differ on the remainder, and the calculator leaves it unassigned.
Two special cases
When the only heirs are a spouse and both parents, the mother receives a third of what remains after the spouse's share, and the father the rest. These are known as the 'Umariyyatan cases.
Questions
What comes out of the estate before it is divided?
Funeral costs, then debts, then any bequest (wasiyya). A bequest cannot exceed one third of what is left after debts. The rest is divided among the heirs by their fixed shares.
Why does a son get twice a daughter's share?
Qur'an 4:11 sets a son's share at twice a daughter's when they inherit together.
What is awl?
When the fixed shares add up to more than the whole estate, every share is reduced in proportion so they fit. For example, a husband (1/2) and two full sisters (2/3) become 3/7 and 4/7.
What is radd?
When the fixed shares add up to less than the whole and no residuary heir is left, the surplus is returned to the fixed-share heirs in proportion. In the view used here the spouse does not share in it.
Does this cover grandchildren or grandparents?
Not yet. This version covers spouses, children, parents and full siblings. For any other relative, or a disputed case, ask a scholar or an Islamic will service.
Based on Qur'an 4:11, 4:12 and 4:176 and the classical rules of awl, radd and the 'Umariyyatan cases, pending review by a scholar. See sources and method. Not legal advice.