CalcaTools

Waqf Endowment Calculator | Project distributions & corpus growth

Projects a waqf endowment's annual distributions and corpus growth, and checks whether the payout rate is sustainable against expected halal returns and inflation.

Last updated: June 2026 · Free · No sign-up required

$
%

Sukuk, halal equity funds or rental real estate.

%
%
Results

Enter values above and click Calculate to see your result instantly.

A waqf is Islam’s perpetual charity machine: the principal is locked forever and only its returns are spent — which is why a single well-run endowment can fund a mosque or school for centuries. The catch is arithmetic: distribute more than your real return and the corpus quietly consumes itself. This calculator runs the projection year by year and tells you plainly whether your payout rate is sustainable.

Enter the principal, the expected return from Shariah-compliant investments, the annual payout and inflation. You get the first-year distribution, total distributed over the horizon, the corpus in both nominal and today’s money, and the inflation-proof payout ceiling — the maximum rate at which the waqf truly lasts forever.

Quick reference

PrincipalReturnPayoutFirst-year distributionSustainable?
$100,0007%4%$4,000Yes (ceiling 4% at 3% inflation)
$100,0005%6%$6,000No — erodes real corpus
$500,0006%3%$15,000Yes
$1,000,0007%4%$40,000Yes

info Waqf (Endowment) Calculator

Free islamic calculator — enter your numbers and get an instant, accurate result.

info Private by design

Everything runs locally in your browser. No uploads, no accounts, no tracking.

info Works everywhere

Fully responsive and mobile-friendly — calculate on any device, any time.

info Educational

Includes the formula and step-by-step explanation so you understand the math, not just the answer.

Interpretation guide

CheckWhat it means
Payout ≤ return − inflationCorpus keeps its real value forever — a true perpetual waqf
Payout = returnNominal corpus flat, but inflation quietly shrinks it
Payout > returnCorpus declines in nominal terms — the waqf consumes itself
Real corpus columnFuture corpus expressed in today's purchasing power

lightbulb Worked example

Let's say you are using the Waqf (Endowment) Calculator. Projects a waqf endowment's annual distributions and corpus growth, and checks whether the payout rate is sustainable against expected halal returns and inflation. Enter the values that match your situation into the input fields and press calculate — using realistic numbers makes the result directly useful for you.

Result: The calculator instantly applies the formula Sustainable payout ≤ return − inflation; corpus(t) = corpus(t−1) × (1 + return) − distribution and returns the result with appropriate precision.

What this means: Read the result in the context of what you are measuring. The step-by-step breakdown lets you confirm the math and understand which input most affects the outcome.

Formula & methodology

Formula: Sustainable payout ≤ return − inflation; corpus(t) = corpus(t−1) × (1 + return) − distribution

The Waqf (Endowment) Calculator is built on a well-established calculation method. It uses the formula Sustainable payout ≤ return − inflation; corpus(t) = corpus(t−1) × (1 + return) − distribution to turn your inputs into a reliable result. Projects a waqf endowment's annual distributions and corpus growth, and checks whether the payout rate is sustainable against expected halal returns and inflation. The steps are shown on the page so you can follow the reasoning from input to output.

  1. Enter the endowed principal and the expected annual return from Shariah-compliant investments (sukuk, halal equity, rental property).
  2. Set the payout rate distributed to beneficiaries each year and expected inflation.
  3. The simulator distributes, then grows the remaining corpus, year by year, and reports the inflation-proof payout ceiling.

Worked example: $100,000 waqf earning 7% with a 4% payout and 3% inflation distributes $4,000 in year 1 and $145,837 over 25 years, while the corpus grows to $209,378 — exactly $100,000 in today's money: the maximum payout that preserves it forever.

Authoritative source: Islamic Relief

Frequently asked questions

What is a waqf?
A waqf is a permanent Islamic endowment: an asset is dedicated to Allah, its principal locked forever, and only its returns are spent on the designated cause — mosques, schools, wells, the poor. It is the classic vehicle for sadaqah jariyah.
How much can a waqf pay out sustainably?
The Waqf (Endowment) Calculator is free, private, and accurate: it runs entirely in your browser (no uploads, no accounts), applies the standard calculation, and explains each step so you can verify the result. Projects a waqf endowment's annual distributions and corpus growth, and checks whether the payout rate is sustainable against expected halal returns and inflation. There is no limit on usage, and it works on any device.
Can a waqf principal be spent?
No — the defining feature of a waqf is that the principal (the corpus) is permanent and cannot be spent; only the income or returns from it may be distributed. Spending the principal would break the endowment's purpose. The calculator enforces this by projecting the corpus with returns minus distributions, and it flags when the payout rate would eat into the principal.
What investments can a waqf hold?
A waqf's corpus is typically invested conservatively in income-producing, shariah-compliant assets — real estate (rental property is the classic choice), Islamic funds and sukuk, or halal equities — avoiding interest-bearing instruments. The calculator's return assumption should reflect this conservative profile, typically 4–7% annually, with the sustainable payout rate set below the return minus inflation.
Does zakat apply to a waqf?
Yes — the Waqf (Endowment) Calculator is fully responsive and works in any modern browser on a phone, tablet, or desktop, with touch-sized inputs and no app to install. The full calculation runs on the device, so you get the same speed and precision on mobile as on a computer, even with a weak connection.
What does the Waqf (Endowment) Calculator do?
Projects a waqf endowment's annual distributions and corpus growth, and checks whether the payout rate is sustainable against expected halal returns and inflation. The calculator takes your inputs, applies the standard calculation, and returns a clear result so you can make an informed decision without doing the math by hand.
What formula does the Waqf (Endowment) Calculator use?
It projects corpus growth with corpus(t) = corpus(t−1) × (1 + return) − distribution and flags a payout as sustainable when it does not exceed return − inflation. Enter the endowment amount, expected halal return, inflation, and annual distribution, and the tool shows how many years the corpus lasts and whether the payout rate is sustainable long-term.
Is the Waqf (Endowment) Calculator free and private?
Yes — the Waqf (Endowment) Calculator. There is no sign-up, no paywall, no trial, and no limit on how many calculations you can run. CalcaTools covers its costs with non-intrusive display advertising, so the calculator itself never asks for payment or restricts any feature.
How accurate is the Waqf (Endowment) Calculator?
The Waqf (Endowment) Calculator applies the standard formula: Sustainable payout ≤ return − inflation; corpus(t) = corpus(t−1) × (1 + return) − distribution. It is tested against published worked examples before launch and uses native double-precision arithmetic, so results are accurate to typical precision for the values you enter — with no intermediate rounding that could distort the answer.

Explore the full Islamic toolkit

Every CalcaTools Islamic calculator — zakat and charity, prayer times, the Hijri calendar, halal finance, and family tools — cross-checked against the Umm al-Qura calendar and classical fiqh references.

Zakat & charity

Prayer & worship

Hijri calendar & dates

Halal finance & pilgrimage

Family & lifestyle

More Islamic tools