How we calculate

Our calculators use standard, published methods. Here's what they assume, so you know when your statement might differ.

Our standards

• Formulas follow the methods described by the Consumer Financial Protection Bureau and in issuers' cardholder agreements.
• Each calculator page shows its formula, its assumptions and a worked example.
• We test every calculator against hand calculations before publishing and after every change.
• Pages show the date they were last reviewed. Formulas reviewed September 29, 2026.

Common assumptions

• Monthly compounding. Payoff, minimum payment and balance transfer calculators apply APR ÷ 12 each month. Issuers compound daily, so real totals can differ by a few dollars.
• No new purchases. Payoff estimates assume you stop adding to the balance.
• Constant APR. Variable APRs can change with the prime rate.
• Payments on time. Late payments can trigger fees and a penalty APR.

Guides and card facts

Card rates and fees in our guides are checked against the issuer's own product page or cardholder agreement, and each guide shows the date it was last verified. Advertisers can't review or change our content.

Corrections

If we get something wrong, we fix it and note material corrections on the page. Report an error.