The estate is settled in an order
The calculator begins with the gross estate, then deducts reasonable funeral and burial costs, enforceable debts and a valid bequest. Only the balance is divided between heirs. A bequest is normally limited to one third after costs and debts, and a bequest for an existing Islamic heir has additional consent rules.
Prescribed shares
The central Quranic passages are Surah An-Nisa 4:11, 4:12 and 4:176. They prescribe shares for children, parents, spouses and siblings in defined circumstances. The table below summarises the common starting shares. Conditions and exclusions still have to be applied.
| Heir | Common prescribed share | Main condition |
|---|---|---|
| Husband | 1/2 or 1/4 | One half without descendants; one quarter with descendants. |
| Wife or wives | 1/4 or 1/8 collectively | One quarter without descendants; one eighth with descendants. |
| One daughter | 1/2 | No son. |
| Two or more daughters | 2/3 collectively | No son. |
| Mother | 1/3 or 1/6 | Reduced to one sixth by descendants or two or more siblings. |
| Father | 1/6 and/or residue | One sixth with descendants; may also take residue. |
| One maternal sibling | 1/6 | No descendant, father or paternal grandfather. |
| Two or more maternal siblings | 1/3 collectively | They share equally, regardless of sex. |
| One full sister | 1/2 | In a qualifying kalalah case without a full brother. |
| Two or more full sisters | 2/3 collectively | In a qualifying kalalah case without a full brother. |
Residuary heirs
After prescribed shares are assigned, the balance passes to the nearest eligible residuary heir. Sons and daughters together share the residue in a two-to-one ratio. The same pattern applies to other male and female residuary pairs at the same degree, such as full brothers with full sisters.
The general priority moves from descendants to ascendants and then to collateral male relatives: son, son's son, father, paternal grandfather, full brother, paternal half-brother, nephews, paternal uncles and paternal cousins. A nearer residuary excludes a more distant one.
Blocking and reduction
Hajb means that the presence of one heir affects another. Complete exclusion removes a more distant heir entirely. Partial exclusion reduces a share, such as a husband's share falling from one half to one quarter when the deceased has descendants.
| Heir affected | Commonly affected by | Effect |
|---|---|---|
| Son's descendants | Son | Completely excluded. |
| Paternal grandfather | Father | Completely excluded. |
| Grandmothers | Mother | Completely excluded. |
| Full siblings | Son or father | Completely excluded. |
| Paternal half-siblings | Full brother | Generally excluded. |
| Maternal siblings | Descendant, father or paternal grandfather | Completely excluded. |
| Spouse | Descendants | Share is reduced, not removed. |
| Mother | Descendants or two or more siblings | Reduced from one third to one sixth. |
Two heirs are not interchangeable merely because their everyday descriptions sound similar. A daughter, son's daughter and adopted daughter have different legal positions. The result therefore names each relationship precisely.
Awl, radd and named cases
Awl
When the prescribed fractions total more than the estate, every prescribed share is reduced proportionally. For example, a husband and two full sisters initially claim 1/2 plus 2/3. The common denominator rises from six to seven, producing 3/7 and 4/7.
Radd
When prescribed shares total less than the estate and there is no residuary, the balance may return proportionally to eligible prescribed-share heirs. In the default method used here, a spouse does not join radd while another eligible prescribed-share heir exists. If only a spouse remains, the undistributed balance is flagged because classical doctrine, modern legislation and the treatment of distant kindred differ.
Umariyyatain
When the only heirs are a spouse, mother and father, the mother receives one third of what remains after the spouse. This preserves a two-to-one balance between the father and mother.
Grandfather with siblings and Akdariyyah
The calculator uses the approach associated with Zayd ibn Thabit for the paternal grandfather competing with siblings. It compares one sixth of the whole estate, one third of the remainder and sharing as one brother, then applies the most favourable valid option for the grandfather. Akdariyyah receives its recognised special adjustment.
Recognised differences of opinion
This calculator is majority-oriented rather than tied silently to one school. Where recognised positions produce materially different answers, the result displays a review warning. That is especially important for the Mushtarakah or Himariyyah, mixed grandfather and sibling cases, radd to spouses, distant kindred and the operation of a public treasury.
Local inheritance legislation may also adopt one school, combine opinions or impose mandatory bequests. A mathematically correct faraid result is not automatically a legally effective distribution in every country.