How much interest you'll pay on a card balance.
These calculators use standard financial formulas (amortization, compound interest, marginal tax brackets) to estimate results based on the numbers you enter. They don't account for your full financial picture, and results shouldn't be treated as financial, tax, or investment advice. For decisions with real money on the line, check the numbers with a lender, accountant, or financial advisor who can see your complete situation.
Credit card interest is calculated daily on the outstanding balance and compounded monthly. Small payments mean most goes to interest and the balance barely moves.
This assumes a fixed monthly payment; real cards let you pay a percentage-based minimum that keeps you in debt for decades.
Because interest compounds daily rather than monthly, credit card debt grows faster than an amortized loan of the same nominal APR — which is part of why it feels so much harder to pay down than a mortgage or car loan.
$3,000 at 22% APR, $100/month: takes about 44 months and costs $1,395.30 in interest — nearly half the original balance again.
High APRs (18–29%) plus low minimums (1–3%) mean minimums barely dent principal. Doubling or tripling dramatically speeds payoff.
A 0% intro APR transfer helps if you pay it off before the intro ends. Watch for transfer fees (3–5%).
Slightly — reduces average daily balance. Paying a larger total matters far more than splitting it.
Concentrate extra payments on the highest-APR card while paying minimums on the rest — this is the avalanche method and mathematically saves the most interest overall.