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Islamic inheritance law (Ilm al-Fara'id) is one of the most precisely codified legal systems in religious law, allocating shares of a deceased Muslim's estate among heirs according to Quranic injunctions and detailed rulings developed by Islamic scholars over 1,400 years. The Quran dedicates two substantial passages to inheritance (Surah An-Nisa, verses 11–12 and 176), specifying exact fractional shares for many categories of heirs. The Prophet Muhammad (PBUH) called knowledge of inheritance law one of the first sciences that would be forgotten and urged its study. Unlike many legal systems that allow complete testamentary freedom, Islamic inheritance law operates on a mandatory share system: only one-third of the estate (at most) can be distributed by will (wasiyyah) to non-heirs or charity, while the remaining two-thirds must be distributed to Quranic heirs by their specified fractions. Primary heirs (ashabul-furudh) include spouses (1/4 or 1/8), daughters (1/2 if sole, 2/3 if multiple), sons (residuary heir, double a daughter's share), mothers (1/6 or 1/3), fathers (1/6 plus residuary), and others. The residuary (asabat) heirs — primarily sons and paternal relatives — receive what remains after Quranic shares are distributed. The calculator implements the classical Hanafi, Maliki, Shafi'i, and Hanbali school calculations, which occasionally differ in edge cases. Given that Muslims manage approximately $3.7 trillion in combined household wealth in the US, UK, and Europe alone, proper Islamic estate planning has significant real-world financial implications.
Net Estate = Gross Estate − Debts − Funeral Expenses − Wasiyyah (max 1/3) Quranic Shares: - Husband: 1/4 (if children exist), 1/2 (no children) - Wife/Wives: 1/8 (if children), 1/4 (no children) — shared among all wives - Daughter (sole): 1/2 | Multiple daughters: 2/3 shared - Son: Residuary (double daughter's share in mixed scenario) - Mother: 1/6 (if children), 1/3 (no children, no siblings) - Father: 1/6 (if son exists), residuary (if no son) Example: Estate = $300,000 after debts | Heirs: Wife, Son, Daughter Wife's share = 1/8 = $37,500 Remainder = $262,500 split Son:Daughter (2:1) Son = $175,000 | Daughter = $87,500
- 1Enter the total value of the net estate (after debts, funeral costs, and any valid wasiyyah up to 1/3).
- 2Input all surviving heirs and their relationship to the deceased (spouse, children, parents, siblings, etc.).
- 3Select the madhab (school of Islamic law) to apply, as Hanafi, Maliki, Shafi'i, and Hanbali schools differ in certain edge cases.
- 4The calculator identifies each heir's Quranic share (faridah) or residuary status (asabah) and computes the monetary amount.
- 5Cases of 'aul' (proportional reduction when shares exceed the estate) and 'radd' (return of surplus to heirs when shares are less) are handled automatically.
- 6The results are displayed as fractions, percentages, and monetary amounts — and can be exported as a formal estate distribution statement.
Wife takes 1/8 as children exist; remaining 7/8 goes to sons and daughter in 2:1 ratio per classical Islamic law.
A sole daughter receives 1/2; the remaining half returns to the father's lineage (asabah). If no paternal relatives exist, radd doctrine returns it to the daughter.
Husband takes 1/2 (no children); mother takes 1/3 of the remainder; father takes the residual.
Three or more daughters share 2/3; mother takes 1/6; full brothers take the residual as asabah heirs.
Professionals in finance and lending use Islamic Inheritance Calc as part of their standard analytical workflow to verify calculations, reduce arithmetic errors, and produce consistent results that can be documented, audited, and shared with colleagues, clients, or regulatory bodies for compliance purposes.
University professors and instructors incorporate Islamic Inheritance Calc into course materials, homework assignments, and exam preparation resources, allowing students to check manual calculations, build intuition about input-output relationships, and focus on conceptual understanding rather than arithmetic.
Consultants and advisors use Islamic Inheritance Calc to quickly model different scenarios during client meetings, enabling real-time exploration of what-if questions that would otherwise require returning to the office for detailed spreadsheet-based analysis and reporting.
Individual users rely on Islamic Inheritance Calc for personal planning decisions — comparing options, verifying quotes received from service providers, checking third-party calculations, and building confidence that the numbers behind an important decision have been computed correctly and consistently.
The Hanafi school applies 'radd' (returning surplus shares to heirs
The Hanafi school applies 'radd' (returning surplus shares to heirs proportionally) in all cases, while some other schools exclude the spouse from radd beneficiaries.
'Aul' (proportional reduction) occurs when the sum of all fixed shares exceeds
'Aul' (proportional reduction) occurs when the sum of all fixed shares exceeds the whole estate (100%) — all shares are reduced proportionally, with no residual. The classical example involves a husband (1/2), two full sisters (2/3), and a mother (1/6) totaling 14/12 — requiring aul.
Grandchildren are generally excluded when a son or daughter survives (they are
Grandchildren are generally excluded when a son or daughter survives (they are 'blocked' by the parent), which can lead to a grandchild losing out if their parent predeceased the grandparent — addressed in many Muslim-majority countries by 'mandatory bequest' laws.
| Heir | Share (with children) | Share (without children) | Conditions | Quran Reference |
|---|---|---|---|---|
| Husband | 1/4 | 1/2 | Only one husband | 4:12 |
| Wife/Wives (shared) | 1/8 | 1/4 | All wives share equally | 4:12 |
| Father | 1/6 | 1/6 + residuary | Blocked by no one | 4:11 |
| Mother | 1/6 | 1/3 | Reduced if siblings exist | 4:11 |
| Sole Daughter | 1/2 | 1/2 | No son co-heir | 4:11 |
| Multiple Daughters | 2/3 shared | 2/3 shared | No son co-heir | 4:11 |
| Son | Residuary | Residuary | Double daughter's share | 4:11 |
Is Islamic inheritance law mandatory for Muslims?
Islamic scholars widely hold that following Fara'id (inheritance law) is obligatory (fard) for Muslims, as it is explicitly prescribed in the Quran. However, in Western countries, civil law governs estates, so Muslims must use Islamic wills drafted by specialized attorneys (and recognized under civil law) to align their inheritance with Islamic requirements.
Why do daughters receive half of sons in Islamic inheritance?
In the context of Islamic Inheritance Calc, this depends on the specific inputs, assumptions, and goals of the user. The underlying formula provides a deterministic relationship between inputs and output, but real-world application requires interpreting the result within the broader context of finance and lending practice. Professionals typically cross-reference calculator output with industry benchmarks, historical data, and regulatory requirements. For the most reliable results, ensure inputs are sourced from verified data, understand which assumptions the formula makes, and consider running multiple scenarios to bracket the range of likely outcomes.
Can a Muslim disinherit a child or spouse?
No — Islamic law does not permit disinheriting Quranic heirs from their mandated shares. However, one-third of the estate (wasiyyah) can be allocated by will to non-heirs, charities, or causes not otherwise entitled. This 'free third' cannot be used to give more to one heir at the expense of others.
Can non-Muslim relatives inherit from a Muslim?
In the context of Islamic Inheritance Calc, this depends on the specific inputs, assumptions, and goals of the user. The underlying formula provides a deterministic relationship between inputs and output, but real-world application requires interpreting the result within the broader context of finance and lending practice. Professionals typically cross-reference calculator output with industry benchmarks, historical data, and regulatory requirements. For the most reliable results, ensure inputs are sourced from verified data, understand which assumptions the formula makes, and consider running multiple scenarios to bracket the range of likely outcomes.
What happens to the estate if there are no Quranic heirs?
In the context of Islamic Inheritance Calc, this depends on the specific inputs, assumptions, and goals of the user. The underlying formula provides a deterministic relationship between inputs and output, but real-world application requires interpreting the result within the broader context of finance and lending practice. Professionals typically cross-reference calculator output with industry benchmarks, historical data, and regulatory requirements. For the most reliable results, ensure inputs are sourced from verified data, understand which assumptions the formula makes, and consider running multiple scenarios to bracket the range of likely outcomes.
How do I make an Islamic will (wasiyyah)?
In the context of Islamic Inheritance Calc, this depends on the specific inputs, assumptions, and goals of the user. The underlying formula provides a deterministic relationship between inputs and output, but real-world application requires interpreting the result within the broader context of finance and lending practice. Professionals typically cross-reference calculator output with industry benchmarks, historical data, and regulatory requirements. For the most reliable results, ensure inputs are sourced from verified data, understand which assumptions the formula makes, and consider running multiple scenarios to bracket the range of likely outcomes.
Does Islamic inheritance apply to pension funds and life insurance?
Classical Fara'id rules apply to assets owned at death. Modern assets like pension funds, life insurance, and jointly-owned property follow civil law designation rules. Muslim financial planners recommend specifying beneficiaries on these accounts in a way consistent with Islamic inheritance wishes, though this is a complex area requiring scholarly guidance.
プロのヒント
Every Muslim adult should have an Islamic will in place. Work with an attorney experienced in Islamic estate planning — organizations like the American Muslim Bar Association or UK's Islamic Will services can refer qualified practitioners. Review and update your will after every major life event (marriage, birth, death of a potential heir, major asset acquisition).
ご存知でしたか？
The Ottoman Empire codified Islamic inheritance law into the Mecelle (a comprehensive Islamic civil code completed in 1876), which influenced legal systems across the Middle East, the Balkans, and Central Asia for over a century. Elements of Fara'id remain part of family law in 50+ countries today, including Egypt, Jordan, Malaysia, Pakistan, and Saudi Arabia.