All calculators

11 free tools. Every one shows the complete number, publishes its formula, and works without an account.

What these do differently

Most free financial calculators are lead generation. The tool is not the product - your contact details are, and they are sold to somebody who wants to sell you a loan, a policy or a system. That arrangement has a predictable effect: the calculator is paid more when the answer is encouraging, so the version with the cheerier assumptions is the version that survives.

These collect nothing. No account, no email field, no phone number, and nothing you type is stored or sold. With nothing to sell, there is no reason to flatter you.

In practice that shows up as larger numbers, not smaller ones. A mortgage payment here includes property tax, insurance, PMI and HOA, because that is what actually leaves your account - the principal and interest figure quoted on a listing is routinely a quarter to a third short. PMI is modelled running and then dropping off automatically at 78% loan-to-value, which is the statutory threshold, rather than being charged for thirty years or ignored entirely.

How to read a result

Every calculator here prints its formula and names its assumptions. Where a figure is genuinely an input - an interest rate, a tax rate, a growth assumption - it is yours to set rather than a national average dressed up as a fact about your situation. A state-level property tax figure would be false precision, because the rate is set locally enough to differ between two towns in the same county.

Long projections deserve particular caution. Small differences in a growth rate compound into large differences in a total, so treat a thirty-year figure as an indication of scale rather than a prediction. Where a result depends heavily on one assumption, change it and watch how far the answer moves - if it moves a lot, that assumption is the thing to get right, not the arithmetic.

Where to start

If you are buying a home, start with the mortgage calculator for the complete payment, then the affordability calculator to work backwards from what you are willing to pay each month rather than forwards from the largest loan you could be approved for. Those are different numbers and only one of them is about your life.

If you are carrying balances, the debt payoff and credit card payoff calculators show what the interest is actually costing and how much sooner it ends if you pay more than the minimum. If you are planning further out, compound interest and the retirement withdrawal tools cover the accumulation and the drawdown - and the drawdown is the half most people never model.