How To Calculate Mother-in-Law's Share

Today, we'll be covering the Islamic inheritance rules for mothers-in-law, their position within the inheritance system, and practical examples to help you understand how a mother-in-law's inheritance is calculated according to Shariah law.
Key Takeaways
- A mother-in-law does not automatically inherit from her son-in-law or daughter-in-law under Islamic inheritance law
- The mother-in-law is considered an extended family member without a direct inheritance relationship to her children's spouses
- Islamic law recognizes only blood relations, marriage, and special relationships as bases for inheritance
- A mother-in-law can receive up to one-third of the estate through a voluntary bequest (wasiyyah)
- Understanding the mother-in-law's position helps families plan appropriately for wealth distribution according to Islamic principles
Understanding a Mother-in-Law's Position in Islamic Inheritance
In Islamic inheritance law, heirs are categorized based on their relationship to the deceased. The primary categories that establish inheritance rights are:
- Blood relations (nasab): Parents, children, siblings, and other blood relatives
- Marriage (nikah): Spouses
- Wala' (special relationship): Historically, this referred to the relationship between a freed slave and the one who freed them
A mother-in-law, being the mother of one's spouse, does not fall into any of these categories in relation to her son-in-law or daughter-in-law. She is neither a blood relative nor a spouse of the deceased, which means she does not automatically qualify as an heir under Islamic inheritance law.
The Quran explicitly mentions the shares of specific relatives in Surah An-Nisa (4:11-12, 4:176), but mothers-in-law are not included among those with fixed shares. This omission is significant as it indicates that mothers-in-law are not considered among the primary or secondary heirs in Islamic inheritance.
Mother-in-Law's Inheritance Status
No Automatic Inheritance Right
According to all major schools of Islamic jurisprudence (Hanafi, Maliki, Shafi'i, and Hanbali), a mother-in-law does not automatically inherit from her son-in-law or daughter-in-law. This ruling is consistent across traditional and contemporary Islamic scholarship.
The reason for this exclusion is that Islamic inheritance is primarily based on direct blood relationships and marriage. Since a mother-in-law is related to the deceased only through marriage to her child, and not directly to the deceased, she does not qualify as an automatic heir.
Comparison with Other In-Laws
Similar to mothers-in-law, other in-laws such as fathers-in-law, brothers-in-law, and sisters-in-law also do not automatically inherit from their relatives by marriage. The only exception to this rule is between spouses themselves, who inherit from each other based on their direct marriage relationship.
This principle is derived from the hadith of the Prophet Muhammad (peace be upon him): "Give the shares to those who are entitled to them, and whatever remains goes to the nearest male relative." Since in-laws are not among those entitled to fixed shares, they do not inherit automatically.
Alternative Provisions for Mothers-in-Law
While a mother-in-law does not automatically inherit, Islamic law provides several mechanisms through which she can be financially supported:
1. Wasiyyah (Bequest)
The most common way to provide for a mother-in-law is through a wasiyyah (bequest). According to Islamic law, a person can allocate up to one-third of their estate to non-heirs through a will. This provision allows individuals to leave a portion of their wealth to their mothers-in-law if they wish to do so.
The one-third limitation ensures that the rights of legal heirs are protected while still allowing flexibility to provide for those who do not automatically inherit. This principle is based on the hadith where the Prophet Muhammad (peace be upon him) advised Sa'd ibn Abi Waqqas:
"One-third, and one-third is a lot." (Bukhari and Muslim)
2. Gifts During Lifetime (Hibah)
Another way to provide for a mother-in-law is through gifts during one's lifetime. These gifts are not subject to inheritance rules and can be given in any amount. This approach allows individuals to support their mothers-in-law while they are still alive, which can be more beneficial than waiting until after death.
3. Family Endowment (Waqf)
Creating a family endowment (waqf) that benefits the mother-in-law is another option. A waqf is a charitable endowment that can be established to provide ongoing support for specified beneficiaries, including family members who are not legal heirs.
Practical Examples and Scenarios
Example 1: Son-in-Law's Estate
A man dies leaving behind his wife, two children, parents, and mother-in-law. The estate is valued at $300,000.
Calculation: - Wife's share: 1/8 (with children) = $37,500 - Two children: Residuary heirs (son receives twice the share of daughter) - Son: 2/3 of remaining $262,500 = $175,000 - Daughter: 1/3 of remaining $262,500 = $87,500 - Father's share: 1/6 = $50,000 - Mother's share: 1/6 = $50,000 - Mother-in-law: No automatic share
If the man had made a wasiyyah allocating one-third of his estate to his mother-in-law, the calculation would be different: - Wasiyyah to mother-in-law: 1/3 of $300,000 = $100,000 - Remaining $200,000 distributed among legal heirs according to their proportional shares
Example 2: Daughter-in-Law's Estate
A woman dies leaving behind her husband, one child, parents, and mother-in-law. The estate is valued at $240,000.
Calculation:
- Husband's share: 1/4 (with child) = $60,000
- Child's share: Residuary heir = $120,000
- Father's share: 1/6 = $40,000
- Mother's share: 1/6 = $40,000
- Mother-in-law:
- Status: No automatic share under Islamic inheritance law
- May be included through wasiyyah (bequest) of up to one-third if desired
If the woman had made a wasiyyah allocating one-fifth of her estate to her mother-in-law, the calculation would be:
- Wasiyyah to mother-in-law: 1/5 of $240,000 = $48,000
- Remaining $192,000 distributed among legal heirs according to their proportional shares
Cultural Practices vs. Islamic Law
It's important to distinguish between cultural practices and Islamic legal requirements regarding mothers-in-law. In many Muslim societies, there are strong cultural expectations to care for parents-in-law, particularly in their old age.
While these cultural norms are valuable and often align with Islamic ethics of family care, they should not be confused with the specific legal framework of Islamic inheritance.
Some cultural practices may include:
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Joint family living: In many Muslim cultures, daughters-in-law and sons-in-law live with their parents-in-law, providing direct care and support.
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Financial support: Cultural expectations often include financial support for parents-in-law, especially when they are elderly or in need.
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Informal wealth distribution: Some families may follow cultural patterns of wealth distribution that differ from strict Islamic inheritance rules.
While these practices are commendable from a social and ethical perspective, they do not alter the formal Islamic inheritance framework. Muslims are encouraged to fulfill their cultural and moral obligations to parents-in-law while also adhering to the legal requirements of Islamic inheritance.
Differences Across Schools of Islamic Jurisprudence
All four major Sunni schools of thought (Hanafi, Maliki, Shafi'i, and Hanbali) agree that mothers-in-law do not automatically inherit from their sons-in-law or daughters-in-law. However, there are some differences in how these schools approach related issues:
Hanafi School
- Emphasizes the importance of wasiyyah for non-heirs
- Allows for the inheritance of distant relatives (dhawil arham) in the absence of primary heirs
- A mother-in-law might inherit if she has another relationship to the deceased that qualifies her as an heir
Maliki School
- Strictly adheres to the principle that only specified heirs inherit
- Does not typically recognize the inheritance rights of distant relatives
- Emphasizes the moral obligation to care for relatives, including in-laws
Shafi'i School
- Similar to the Maliki school in limiting inheritance to specified heirs
- Emphasizes the importance of wasiyyah for those who do not automatically inherit
- Recognizes the moral obligation to care for in-laws without granting them inheritance rights
Hanbali School
- Allows for the inheritance of distant relatives in the absence of primary heirs
- Emphasizes the importance of wasiyyah for non-heirs
- Recognizes the moral obligation to care for in-laws
Jafari (Shia) School
- Similar to Sunni schools in not granting automatic inheritance rights to mothers-in-law
- Allows for wasiyyah to non-heirs
- May have different rules regarding the distribution of the estate in the absence of primary heirs
Modern Applications and Considerations
Estate Planning for Muslim Families
Modern Muslim families often face complex situations regarding in-laws, particularly in multicultural or multinational contexts. Effective estate planning should consider:
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Creating a valid Islamic will: This should specify any portion (up to one-third) that you wish to allocate to your mother-in-law or other non-heirs.
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Balancing cultural expectations with legal requirements: Understanding both the cultural norms and Islamic legal framework helps families make informed decisions.
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Consulting experts: Seeking advice from Islamic scholars and legal experts specialized in Islamic inheritance ensures compliance with both religious and civil law.
Legal Implementation in Muslim-Majority Countries
Most Muslim-majority countries have codified Islamic inheritance laws into their legal systems, though with some variations:
- Egypt: Follows Hanafi school with some reforms
- Malaysia: Applies Islamic inheritance law for Muslims
- Saudi Arabia: Strict application of Hanbali school
- Pakistan: Islamic inheritance laws with some modern adaptations
These legal systems generally do not recognize automatic inheritance rights for mothers-in-law but may provide other mechanisms for their support.
Muslims in Non-Muslim Countries
Muslims living in non-Muslim countries face additional challenges in implementing Islamic inheritance rules:
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Creating legally valid wills: These should comply with both Islamic principles and local legal requirements.
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Using trusts and other legal instruments: These can help ensure that wealth is distributed according to Islamic principles.
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Balancing multiple legal systems: Understanding both Islamic law and local civil law is essential for proper estate planning.
Common Questions About Mother-in-Law's Inheritance
Can a Mother-in-Law Ever Inherit Automatically?
A mother-in-law can only inherit automatically if she has another relationship to the deceased that qualifies her as an heir. For example, if a woman is both the mother-in-law and a blood relative of the deceased (which can happen in some cases of intermarriage within families), she would inherit based on her blood relationship, not her status as a mother-in-law.
Is It Obligatory to Leave Something for a Mother-in-Law?
While it is not obligatory to leave a portion of one's estate to a mother-in-law, it is considered a virtuous act to provide for relatives, including in-laws, especially if they are in need. The Quran encourages kindness and generosity toward all relatives:
"Worship Allah and associate nothing with Him, and to parents do good, and to relatives, orphans, the needy, the near neighbor, the neighbor farther away, the companion at your side, the traveler, and those whom your right hands possess." (Quran 4:36)
What If a Mother-in-Law Is Dependent on Her Son-in-Law or Daughter-in-Law?
If a mother-in-law is financially dependent on her son-in-law or daughter-in-law, Islamic ethics encourages continued support for her even after the death of her child's spouse. This can be arranged through:
- A wasiyyah allocating a portion of the estate to her
- Arrangements with the legal heirs to provide for her needs
- Setting up a trust or endowment for her benefit
Can a Wasiyyah for a Mother-in-Law Be Contested?
A wasiyyah that allocates up to one-third of the estate to non-heirs, including a mother-in-law, is valid and should be honored. However, if the wasiyyah exceeds one-third of the estate, the excess portion requires the consent of the legal heirs to be valid.
Conclusion
Islamic inheritance law does not grant automatic inheritance rights to mothers-in-law, as they are not among the heirs specified in the Quran and Sunnah. However, Islamic law provides flexibility through the wasiyyah (bequest) system, allowing individuals to allocate up to one-third of their estate to non-heirs, including mothers-in-law.
If you need an accurate breakdown of inheritance shares based on your family structure, a helpful tool is the Sharia Inheritance Calculator. It ensures fair and Shariah-compliant distribution in line with Islamic guidelines.
References
- The Holy Quran, Surah An-Nisa (4:11-12, 4:176)
- Sahih Al-Bukhari and Sahih Muslim (Hadith collections)
- Al-Mughni by Ibn Qudamah
- Islamic Inheritance Law: A Practical Guide by Muhammad Mustafa Khan
- Fiqh al-Mawarith by Dr. Muhammad Al-Zuhayli
- Resolution No. 183 (19/7) of the International Islamic Fiqh Academy
- AAOIFI Shariah Standard No. 35 on Wills