Division of estate among wife, grandfather and grandson
29-5-2016 | IslamWeb
Question:
Assalaamu alaykum. Please calculate the inheritance according to the following information: - Does the deceased have male relatives who are entitled to inherit: (A son of the son's son) Number 1 (A grandfather [father's side]) - Does the deceased have female relatives who are entitled to inherit: (A wife) Number 1 (A full sister) Number 1
Answer:
All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ʻalayhi wa sallam, is His slave and Messenger.
If the deceased did not leave any other heirs except those mentioned in the question, then the estate should be divided as follows:
The deceased's grandfather gets one-sixth of the estate as a fixed share because the deceased has descendants (children) entitled to inherit. It has been narrated on the authority of ʻImraan ibn Husayn 
that, “A man came to the Prophet, sallallaahu ʻalayhi wa sallam, and said, 'My son's son has died; what do I receive from his estate?' He, sallallaahu ʻalayhi wa sallam, replied, 'You are entitled to a sixth...'” [Ahmad, Abu Daawood, An-Nasaa'i, At-Tirmithi and Ibn Maajah] Imaam Maalik 
commented in his book Al-Muwatta' about the grandfather's share in his grandson's estate, “If the deceased left a grandfather and a son or a grandson, then the grandfather is entitled to one sixth as his allotted share.”
The deceased's wife gets one-eighth of the estate as a fixed share because the deceased has children. Allaah, The Exalted, says (what means): {But if you leave a child, then for them (i.e. the wives) is an eighth of what you leave}[Quran 4:12]
The remainder of the estate (after deducting the fixed shares of the grandfather and wife) should be given to the son's son. The Prophet, sallallaahu ʻalayhi wa sallam, said, “Give the faraa'idh (the shares of inheritance prescribed in the Quran) to those who are entitled to them; and whatever is left should be given to the closest male relative of the deceased.” [Al-Bukhari and Muslim]
The deceased's full sister has no share in the estate because the deceased has a male descendant entitled to inherit. She is excluded by the deceased's grandson. However, it is recommended for the heirs to give a share to the full sister; Allaah, The Exalted, says (what means): {And when (other) relatives and orphans and the needy are present at the (time of) division, then provide for them (something) out of the estate and speak to them words of appropriate kindness.} [Quran 4:8]
Hence, the estate should be divided into twenty-four shares; the grandfather gets one-sixth (four shares), the wife gets one-eighth (three shares), and the remaining seventeen shares are for the son's son.
Allaah knows best.