About IfCalc

IfCalc builds calculators for the financial decisions that are easy to get wrong because the important number is never the one you are shown.

A car dealer quotes a monthly payment. A lender quotes an APR. A listing quotes a price. Each of those is true, and none of them tells you what the thing actually costs you over the years you will own it. Every calculator here exists to close that gap.

How the calculators work

Each one runs entirely in your browser. Nothing you type is sent to a server, stored, or logged — the arithmetic happens on your own device, which is why the results update as you type and why there is no sign-up.

The default values are typical figures meant to give you a sensible starting point, not predictions about your situation. They are there to be changed. The fastest way to learn what actually drives a total is to alter one field at a time and watch which ones move the answer.

Where a calculation depends on an assumption that reasonable people would set differently — a depreciation curve, a charging loss, a share of income — that assumption is an input you can see and adjust, rather than a constant buried in the code.

What we get right, and what we cannot

The mathematics is exact. Every formula is tested against independently calculated reference values before it ships, including the awkward cases: zero-interest loans, ranges entered backwards, budgets that cannot support any payment at all.

The inputs are a different matter. A resale value five years out depends on the specific model, its condition, and a used market nobody can forecast. An insurance premium depends more on the driver than the car. We are careful to say where a figure is an estimate and to let you replace it with a better one.

Who runs this

IfCalc is an independent site run by Dajor Group. It is funded by advertising, which is disclosed on every page where it appears.

Advertisers have no influence over the calculators, the assumptions behind them, or anything written here. No calculator is designed to push you toward a product, and we do not accept payment for favourable treatment. If a calculation shows that borrowing over seven years is expensive, it says so, whoever happens to be advertising alongside it.

Corrections

If you find an error in a formula or an assumption you think is wrong, please tell us — see the contact page. Reports about the mathematics are taken seriously and fixed quickly.