About
About Honest Interest
Five calculators that show what interest does to money you save and money you owe, with the formulas in plain view.
What it is
Honest Interest converts APRs and APYs, compares simple and compound interest, works out credit card payoffs, shows what paying only the minimum costs, and puts a yearly rate on the fees of buy now, pay later plans. Each page explains its formula, gives a worked example and names its sources, mostly the Consumer Financial Protection Bureau's published regulations and research.
Educational use only — not financial advice
The calculators are for learning how the arithmetic works. They are not financial advice, and they do not recommend any card, loan, lender, plan or product. Every rate and fee is a figure you enter; the defaults are neutral examples, not quotes or forecasts. Real accounts can differ: daily interest, fees, promotional rates and changing terms all move the numbers, so check your agreement and statements, and speak to a qualified adviser before making decisions.
Not a bank
Honest Interest is a set of free web calculators. It is not a bank, lender or financial institution, does not offer accounts or credit, and is not connected to any. The passbook look is just a look.
How it works
All the sums run in your browser with plain JavaScript. Nothing you type is sent anywhere, there is no sign-up, and once a page has loaded it keeps working offline. The privacy page lists the one preference stored on your device.