Islamic Fiqh > Inheritance and wasiya > Dividing shares: qasm and aoul
The share division method: the common base, aoul cases (denominator increase) and standard examples.
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Updated on 31 August 2026 at 3:55 AM
The estate is calculated in equal shares that the jurists call "arrows" (siham): every fixed share is brought back to a fraction of the mass. Example from the books: a mother and four paternal uncles: the mother takes the third, the uncles share the two thirds as agnates: the base is three shares, one for the mother, two for the uncles; since the two shares do not spread into whole shares for four heads, one multiplies: two times three equals six. The mother then takes two shares of six, and each uncle one share.
When the fixed shares exceed the base, the denominator of all the heirs is increased proportionally. Example from the books: a husband, the two parents and six daughters: the base is twelve: to the husband three shares (the quarter), to the father two (the sixth), to the mother two (the sixth), to the six daughters eight (the two thirds): total fifteen. The mass rises from twelve to fifteen: the husband three shares, the father two, the mother two, the daughters eight of fifteen; the daughters' fraction no longer falls exactly on the two thirds, but the distribution remains valid; to get whole shares per head, one multiplies the mass by the number of heads of the group: three heads times fifteen equals forty-five shares.
The principle "to the male the share of two females" governs the residue: the agnates share in equal shares where the male counts double the female (agreement; sura an-Nisa 11).
When the mass no longer fits any group, the jurists confront each class's shares with its number of heads and adjust by multiplication, with or without aoul; the faraid books detail these procedures (Al-Ikhtiyar, al-Jawhara an-Nayyira, the Sharh al-Kabir with its glosses).
Every estate calculation follows three steps: set the fixed shares, find the common base, then adjust by aoul or multiplication. The schools' examples provide ready matrices for the most common families.