Credit Card Calculator

Use fixed-payment when you already know what you can afford each month and want to see how long the card takes to clear and how much interest it costs. Use fixed-time when you have a deadline (a wedding fund, a refi closing, the end of a 0% promo) and need the monthly payment that hits it. Use interest-only when you want to see the worst-case cost of paying only the issuer minimum. Use balance-transfer to test whether moving the balance to a 0% promo card actually saves money once the transfer fee is in. The picker at the top of the calculator swaps the inputs to match.

Most US issuer minimums are 1% to 3% of the balance plus that month's interest, with a $25 floor. On a $5,000 balance at 22.9% APR, the first minimum is about $171, of which only the percent-of-balance portion (~$50) chips at principal. As the balance shrinks, the percent slice shrinks with it, so principal contributions decay every month. Federal Reserve and CFPB analyses regularly show minimum-only payoff stretching past 20 years and total interest exceeding the original principal. Use the interest-only mode to see your own numbers, then add even $50/mo on top in fixed-payment mode to watch the timeline collapse.

It depends on three numbers: balance, current APR, and how long the promo window is. The math is simple: transfer fee + promo-APR interest over the window must be less than current-APR interest over the same window. At a 3% fee, a $5,000 balance at 22.9% APR, and a 12-month 0% promo, the transfer costs $150 and saves about $995 in interest. At a 5% fee, low current APR, and a short promo, the fee can outweigh the avoided interest. The balance-transfer mode runs both sides of that comparison so you do not have to. The catch: you need to actually clear the balance before the promo ends, otherwise the standard APR on the new card resets the trap.

US credit cards quote APR as a nominal annual rate. Issuers compute interest in two stages: a periodic rate (APR / 365 for daily-balance cards, or APR / 12 for monthly-balance cards), then they apply it across the billing cycle. For headline math, APR / 12 is the standard monthly approximation, accurate to within a fraction of a percent against daily compounding for typical balances. This calculator uses the APR / 12 convention because it matches what your statement reports as the periodic rate and what the FTC, CFPB, and every major issuer use in their illustrative payoff schedules. If your card statement shows a daily periodic rate, multiply by 365 to recover the APR you should enter here.

Under the 2009 CARD Act (Title I, Section 201), every monthly statement on US revolving credit must show two things: how many months and how much total interest it would take to clear the current balance at the minimum payment alone, and the monthly payment required to clear it in 36 months. The disclosure exists because regulators found the minimum-payment trap was costing consumers tens of billions per year. The interest-only mode in this calculator mirrors the same math the CARD Act forces issuers to publish, so you can see the number before you swipe rather than after.