The Islamic Inheritance Calculator produces a basic faraid estimate: enter the distributable estate and which heirs survive (spouse, mother, father, sons, daughters), and it applies the fixed Quranic shares, assigns the residue to the residuary heirs, and flags the cases, unallocated residue needing radd, or shares exceeding the estate needing 'awl, where qualified scholarship must complete the distribution.
How It Works
Fixed shares are assigned first, depending on whether children survive: a husband takes 1/2 (no children) or 1/4 (with children); wives collectively take 1/4 or 1/8 on the same condition; a mother takes 1/3 or 1/6; a father takes 1/6 with children and may also take residue. Daughters without sons take fixed shares (1/2 for one, 2/3 shared for two or more). What remains goes to the residuary heirs: sons and daughters together at two units per son and one per daughter, or the father where he qualifies as residuary.
Parameters
| Input | Required | Meaning | |---|---|---| | Estate value | Yes | The distributable estate, after funeral costs, debts, and valid bequests | | Sons / daughters | Yes | Counts of surviving children | | Husband or wives | No | Surviving spouse (wives share their portion collectively) | | Mother / father | No | Surviving parents of the deceased |
Worked examples
Residuary children: an estate of 30,000**. The residue of 60,000**, daughter 150,000 left by a wife to a husband, mother, father, and two daughters. Fixed shares are husband 1/4, mother 1/6, father 1/6, daughters 2/3 collectively: in twelfths that is 3 + 2 + 2 + 8 = 15/12, more than the estate. The calculator flags that 'awl is required; under 'awl the denominator becomes 15 and every share scales down proportionally: husband 3/15 (20,000**), father 2/15 (80,000 between them). The radd case: an estate of 15,000), mother 1/3 (25,000) unallocated, which the calculator flags for radd, the return of residue to eligible fixed-share heirs under rules that differ on whether spouses participate.
Reading the flags instead of forcing an answer
The calculator's most valuable outputs are its two refusals. 'Awl (shares exceeding the estate) is resolved by proportional reduction, a doctrine with consensus roots in the practice of the early community, but the calculator leaves its application to a scholar because edge cases in ordering and rounding matter legally. Radd (residue with no residuary heir) is genuinely contested territory across schools, particularly on spousal participation, and other heirs outside this tool's inputs (grandparents, siblings in defined configurations, and more distant residuaries) may take instead. A remainder or an 'awl flag is therefore not an error: it is the tool correctly identifying the boundary of the basic model and telling you the case has entered territory where a mufti or qualified scholar, with the full family tree, must rule.
Before the estate is an estate
The figure you enter must already be the distributable estate, and preparing it has its own ordered steps in Islamic law: reasonable funeral expenses first, then the deceased's debts (including, in many reckonings, unpaid zakat and other obligations), then bequests (wasiyya) to non-heirs, valid up to one third of what remains, and only then the heirs' shares this calculator divides. A bequest to an heir is treated differently (generally invalid without other heirs' consent), debts owed to God and to people have ordering discussions of their own, and assets like jointly held property, insurance payouts, and pension nominations may or may not form part of the estate at all depending on their structure and jurisdiction. Blocked heirs are another boundary: an heir who caused the deceased's death is barred by consensus principle, and difference of religion affects inheritance between relatives, none of which a shares calculator can see in a count of sons and daughters.
Limitations
A basic-shares estimate for the heir set the tool exposes. It does not model grandparents, siblings as heirs, grandchildren through predeceased children, blocking (hajb) rules in full, the grandfather-versus-brothers cases, or school-specific positions, and it does not prepare the estate (debts, bequests, asset classification) or produce a legally effective distribution. Islamic inheritance is applied law in many jurisdictions and interpreted law in others; obtain a qualified scholarly opinion and local legal advice before any distribution.
Frequently Asked Questions
Why do sons receive two units to a daughter's one?
In the residuary division among children, the Quranic allocation assigns a son the share of two daughters (Surah An-Nisa, 4:11). The calculator applies that ratio to the residue after fixed shares, which is why the worked example's 60,000 and $30,000.
The shares add up to more than the estate. Is the calculator broken?
No: that is 'awl, a recognized situation where fixed shares oversubscribe the estate, resolved by scaling all shares down proportionally against a raised denominator, as the second worked example shows. The calculator flags it for scholarly application rather than silently rounding someone out of an entitlement.
What should I do with an unallocated remainder?
Do not distribute it by guesswork. A remainder means radd or additional heirs must be considered, and the schools differ on the treatment. The calculator reports the residue amount explicitly so you can take the exact case, full family tree included, to a qualified scholar.