DebtRunway is built and maintained by Romana Idress Ekfa, an independent full-stack web developer and software engineer. It exists because the Islamic finance calculators already out there hand you a number and stop. A share of an estate means very little until you can see which ruling produced it, and who it excluded.
How the numbers work
The inheritance calculator applies the majority Sunni rules: the fixed shares named in Surah an-Nisa, the residuary heirs who take what is left, the blocking that removes an heir when a nearer one stands in the way, and the awl and radd corrections for when the fractions do not total one. Shares are held as exact fractions rather than decimals, so a sixth plus a sixth plus two thirds is one and not 0.9999.
It is checked against worked examples with settled answers in the classical texts — the awl cases of twelve to fifteen, six to eight and twenty-four to twenty-seven, both Umariyyatan rulings, and every blocking rule. Those checks run as a script in the repository, not as a claim on a page.
The zakat calculator derives the nisab from a metal price you supply, rather than storing a figure that would be wrong within a week, and applies the rate of a fortieth to what remains after debts due now.
Why it is free
The site is supported by advertising. It does not sell your data — there is no data to sell, because every calculation happens in your browser and nothing you type ever leaves your device.
Not a fatwa
These calculators apply rules to the facts you type. They are not a fatwa and not financial advice, and they cannot see a disputed heir, an unborn child, a pension you cannot yet draw, or a question your own school of law answers differently. Take anything that matters to a qualified scholar before acting on it.
Contact
Questions or corrections: hello@debtrunway.com