How is the inheritance calculated for heirs that include a wife, two sons, and a grandfather (father's father)?

If the deceased left no heirs other than a grandfather, a wife, and two sons, then the grandfather receives one-sixth and the wife receives one-eighth due to the presence of a lineal descendant (al-far‘ al-wārith). The remainder goes to the two sons by way of ta‘ṣīb (residuary heirship). The estate is then divided into forty-eight shares: the grandfather receives eight shares, the wife receives six shares, and each son receives seventeen shares. It should be noted that matters of inheritance are complex and intricate, and a mere fatwa is insufficient. Instead, the case must be referred to Sharia courts for investigation and to ensure there are no wills, debts, or other rights that take precedence over the rights of the heirs.