FairShare

FairShare is a free calculator for Islamic inheritance (Fara'id), made by Guiga Labs. You can use it on the web at fairshare.guigalabs.com or as an iOS app, and it works offline.

Why we made it

The Quran spells out inheritance in more detail than almost any other area of law. More verses deal with it than with prayer, fasting or zakat. Yet most calculators we tried picked one school of thought without saying so, got the well-known edge cases wrong (Awl, Radd, Umariatan), or handed back numbers with no explanation.

FairShare tries to fix both problems. It gives the answer under each of the four Sunni schools (Hanafi, Maliki, Shafi'i, Hanbali) plus a General majority view, and it shows how it got there. Every share links to the Quranic verse that sets it.

How the calculator works

The math runs in your browser. The engine is a TypeScript port of the Swift package behind the iOS app, and it uses exact fractions (BigInt under the hood) so the web and iOS results always match. We test it against more than two dozen classical cases, including the named edge cases, so we notice if something breaks.

Calculations you save in the free calculator stay in your browser's IndexedDB and aren't uploaded. You don't need an account to use it, and there are no analytics SDKs or ads. Once the page has loaded, the calculator doesn't talk to a server. FairShare Pro, the paid workspace for attorneys, works differently: it stores your cases in your account.

Who makes it

FairShare is made by Mohammed Guiga, a software engineer in California. Feedback and contributions are welcome. Press materials are at guigalabs.com/fairshare/press.

Before you use it on an actual estate

FairShare is a learning tool. It isn't a religious or legal authority. Dividing an actual estate depends on things a calculator can't know, like debts, bequests (wasiyyah) and local law. For a real distribution, please talk to a qualified mufti and a licensed attorney. The disclaimer has the details.