Paying only the minimum on a typical card balance takes years — often decades — and the interest can exceed the original balance. The reason is structural: the minimum is recalculated from your shrinking balance every month, so the payment shrinks with it, and the payoff stretches out like a horizon. This calculator runs your issuer's actual minimum formula month by month and shows the true timeline, then compares it against freezing the payment and adding a small extra amount.
How issuers build your minimum payment
There is no law that sets your minimum at a particular dollar figure; your card agreement does. Across the major US issuers, two formulas dominate. The most common takes the month's interest plus a percentage of the balance — 1% is the standard slice — which guarantees the payment always covers interest and retires some principal. The alternative is a flat percentage of the balance, typically 2–4%, from which interest is effectively paid first. Layered under both is a floor, usually $25 or $35: when the formula amount falls below the floor, you pay the floor instead (the final payment is simply whatever remains, which can be less).
The distinction sounds academic. It isn't. The interest-plus formula always makes progress, however slowly. The flat formula can fail outright: at a 29.99% APR, interest alone consumes about 2.50% of the balance every month, so a flat 2% minimum doesn't just stall — the balance grows. This calculator treats that case as what it is, a balance that never gets paid off, and shows the fixed monthly payment that would clear it in three or five years instead of a made-up timeline.
The shrinking-payment trap
Because the minimum is a percentage of a falling balance, every payment is smaller than the one before — and a smaller payment retires less principal, so the balance falls more slowly, so the next payment is smaller still. Early on, the effect is invisible; the statement looks almost the same month to month. Compounded over years, it's the difference between a debt and a subscription. The year-by-year table above makes the pattern concrete: watch how much of each year's payments is interest in the early years, and how late the ending balance finally starts to move.
Worked example
Maya owes $5,000 at 24.99% APR. Her issuer's minimum is the month's interest plus 1% of the balance, with a $25 floor — the most common formula in the US market. The calculator is pre-filled with Maya's card.
Her first minimum works out to roughly the month's interest (about $104) plus 1% of the balance ($50) — a manageable-looking $154 or so. The trap is what happens next: that payment only retires $50 of principal, so next month's minimum is smaller, and the month after smaller again. Run the table above and watch the timeline stretch — and then look at the second row of the comparison, where Maya simply keeps paying that first $154 every month. Nothing about her budget changes; only the payment stops shrinking. The difference between those two rows is the entire lesson of this page.
The frozen minimum: the one-change fix
Row two of the comparison is the highest-leverage change available to anyone paying minimums, because it asks for no new money beyond the first month's minimum you were already prepared to pay. You fix the dollar amount instead of accepting each month's recalculated, smaller figure. Every month, the interest portion of that fixed payment shrinks and the principal portion grows — the same mechanics that make a mortgage amortize, applied to a card that was never designed to give you that benefit. Row three shows the same comparison with a steady extra amount on top, which is where a modest raise, a cancelled subscription, or a side income can be pointed with visible effect.
If you carry several cards, the natural next question is which one to attack first — that's a strategy comparison, and it's what the Debt Snowball vs Avalanche Calculator is for. This page's job is narrower and, for a single card, more urgent: knowing what the minimum on this balance actually costs.
How the estimate is calculated
The simulation runs month by month: interest is the balance times APR ÷ 12; the payment follows the formula and floor you selected, capped at the remaining balance plus interest in the final month; totals accumulate until the balance reaches zero, with a 1,200-month (100-year) cap. Real issuers compound interest on daily balances and may define their formula against the statement balance rather than the current one, so treat the output as a close estimate, not a statement-exact figure. Assumptions throughout: no new purchases, no fees, no APR changes — any of the three restarts the clock in real life.