Siblings' Share in Islamic Inheritance

Three Distinct Categories of Siblings

Islamic inheritance law distinguishes carefully between three types of siblings, each with different shares and different conditions for inheriting:

• Full siblings (akhyaf) — share both the same father and mother
• Paternal half-siblings (ala-abi) — share the same father but different mothers
• Uterine/maternal half-siblings (ala-umm) — share the same mother but different fathers

Each category has its own Quranic basis and its own inheritance rules. They are not interchangeable in Faraid calculations.

Full Siblings: Brothers and Sisters

Full brothers are classified as Asabah bi nafsihi — pure residuary heirs who take whatever remains after fixed shares. When a full brother exists alongside full sisters (without any brothers), the full brother enables the sisters to also become Asabah in a 2:1 ratio. A full sister alone receives a fixed share of 1/2; two or more full sisters receive 2/3 to share.

Paternal Half-Siblings

Paternal half-siblings (same father, different mothers) follow the same inheritance pattern as full siblings — but they are ranked below full siblings. The presence of a full brother or two full sisters affects what paternal half-siblings receive:

• One full sister + paternal half-sisters: Full sister takes 1/2 fixed. Paternal half-sisters take 1/6 supplementary (to bring the total daughters' portion to 2/3). If paternal half-brothers also exist, they take the residue.
• Two or more full sisters + paternal half-sisters: Full sisters exhaust the 2/3 maximum. Paternal half-sisters receive nothing (share fully exhausted). Paternal half-brothers also receive nothing.
• Full brother present: Full brother completely blocks all paternal half-siblings.

Uterine (Maternal) Half-Siblings

Uterine siblings — those sharing the same mother but different fathers — have the most restricted inheritance rights. Their shares are prescribed in Surah An-Nisa 4:12: "If a man or woman dies without children and they have a brother or sister [uterine], each of the two gets one-sixth. But if they are more than two, they are partners in a third."

A unique feature of uterine siblings: unlike all other inheritance categories where males receive double females, uterine siblings share equally regardless of gender. The Quranic text explicitly uses "brother or sister" without a 2:1 ratio instruction.

What Blocks Siblings from Inheriting

All siblings are subject to extensive blocking rules. Understanding these is essential for accurate estate calculation:

The Critical Madhab Difference: Grandfather and Siblings

The most significant madhab dispute affecting siblings concerns the paternal grandfather's relationship to siblings when the father is deceased:

• Hanafi madhab: The paternal grandfather steps fully into the father's position and completely blocks all siblings (full, paternal, and uterine). Siblings receive nothing if a grandfather is present.
• Maliki, Shafi'i, Hanbali madhabs: Muqasama applies. The grandfather inherits alongside full siblings as if he were a full brother, guaranteeing himself at least 1/3 of the estate.

This difference can have an enormous practical impact on estate distribution. Our calculator applies the correct rule for whichever madhab is selected.

Worked Example: Estate with Full and Paternal Half-Siblings

Estate: R 480,000. Deceased: male. Heirs: one full sister + one paternal half-brother + one paternal half-sister. No father, no children, no mother.

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Frequently Asked Questions