What are Awl and Radd in Islamic inheritance?

Islamic inheritance fixes the shares of certain heirs directly in the Qur’an. The elegant precision of this system comes with an arithmetical consequence: sometimes the fixed shares add up to more than the estate, and sometimes to less. Both situations need a clear rule. Awl handles the first; Radd handles the second.

Understanding both adjustments matters not because you need to calculate them by hand, but because they explain why the share you receive in a real inheritance may be different from what the bare fraction suggests.

Awl: when shares add up to more than the whole

Sometimes the fixed shares assigned to the heirs total more than 100% of the estate. This happens when several fixed-share heirs are present and their fractions, added together, exceed the whole. The solution is ʿawl — a proportional reduction of every share so that together they fit within the estate.

A worked example: a woman passes away leaving a husband and two full sisters. The husband’s fixed share is one half; the two sisters together receive two thirds. One half plus two thirds equals seven sixths — more than the whole estate. Under ʿawl, both shares are reduced proportionally. The estate is treated as if it were seven parts: the husband receives three parts (his share, reduced proportionally from three sixths), and the sisters together receive four parts (reduced proportionally from four sixths).

When the shares exceed the whole, every heir receives a fair fraction of what is available — no one is simply cut out.

The mechanism ensures that each heir still receives the correct proportion of their entitlement relative to the others. The reduction is fair: everyone takes the same proportional cut.

Radd: when shares add up to less than the whole

The opposite situation also arises. The fixed shares may total less than the estate, and there may be no residuary heir (ʿasabah) to take the remainder. In this case, what happens to the surplus?

The answer is radd — the surplus is returned to the fixed-share heirs, in proportion to their shares. Here the schools differ:

The Hanafi and Hanbali schools apply radd as a general rule, returning the surplus to the fixed-share heirs (with the notable exception that a spouse does not participate in radd). The Maliki and Shafi’i schools historically directed the surplus to the public treasury rather than back to the heirs — though where no functioning treasury exists, contemporary practice in those schools often applies radd as well.