The simplified model.
Order of operations
Pay debts first. Then up to 1/3 Wasiyyah to non-heirs. Then Faraid shares on the remainder.
Spouse
Husband: 1/2 if no children, 1/4 if children. Wife: 1/4 if no children, 1/8 if children (single wife).
Parents
Mother: 1/3 if no children, 1/6 if children. Father: 1/6 fixed share if children present, otherwise residual.
Children
Sons and daughters share the residue in 2:1 ratio (each son receives twice each daughter's share).
What this calculator does NOT cover
Multiple wives, siblings, grandparents, half-blood relations, Awl (proportional reduction when fixed shares exceed unity), Radd (proportional augmentation when fixed shares fall short). Submit unusual cases to Ask the Mufti.
Per MUFTI_CONTENT_POLICY.md, this methodology is editorial. A Mufti Saad signed methodology block replaces this when corpus content covers Faraid in detail.