About CardDebtCalc

There is not much to explain about CardDebtCalc. It is a credit card payoff calculator, and its job is comparing the debt snowball and avalanche repayment methods and shows the monthly payment, total interest and payoff date for each. What follows is how it works, why it exists, and what it does with your data.

Why this site exists

Plenty of personal-finance pages already exist. Most of them make you dismiss a banner, ignore a modal and scroll past filler before the tool appears. CardDebtCalc inverts that: the tool is the page, it compares the debt snowball and avalanche repayment methods and shows the monthly payment, total interest and payoff date for each, and everything else is explanation you can read or skip.

The method behind it

The whole calculation is client-side JavaScript. What happens is this: it simulates month by month, accruing interest at the annual rate divided by twelve and applying your payment to the priority balance — smallest first for snowball, highest-rate first for avalanche — until every balance clears. Because the method is published here, any disagreement you find can be traced to a particular step instead of being blamed on a black box.

Privacy by default

This is a local tool by construction. Your card balances, interest rates and monthly payment never leave your device; there is no endpoint to receive them and no log to read them back from. Disconnecting from the internet after the page loads changes nothing about how it behaves.

Who it is for

Keeping it free

Advertising pays for the running of CardDebtCalc; nothing here is subscription-based. No advertiser is given the values you enter, and an advert appearing beside a tool is never a recommendation of it.

Tell us what you think

Tell us through the contact page if you find a bug or want something added. The credit card payoff calculator improves mainly on the strength of what users report.