Credit Card Payoff Calculator

See how long it takes to pay off your credit card and how much interest you'll pay. Compare different payment strategies.

This calculator simulates a credit card being paid down through a fixed Monthly Payment, month by month (lines 22-81), rather than using a closed-form formula, so it can flag the case where the payment does not even cover that month's interest. Minimum Payment shown on the normal payoff path is a flat 2% of the entered Current Balance (line 13) — it is completely unaffected by APR or Monthly Payment, a genuinely structural inertness rather than a coincidence of these particular defaults. But if Monthly Payment is set low enough that it cannot cover the interest charge in the very first month (below about $91.67 at the default $5,000 balance and 22% APR), the engine switches to a different branch entirely (lines 27-67): Months is set to the sentinel value -1, a message reports "Payment too low to cover interest!", and Minimum Payment is recomputed as the interest charge plus one dollar rather than the 2%-of-balance figure used elsewhere — two different notions of "minimum payment" depending on which branch runs. On the normal path, Months responds most to Monthly Payment (a ±10% span of about 29% of Months) with Current Balance a fairly close second (about 26%) and APR trailing well behind (about 9%). Total Interest, in contrast, is dominated by Current Balance (about 50%), with APR and Monthly Payment much closer to each other (around 30% each) than either is to Balance. This calculator caps the simulation at 600 months and does not model promotional 0% APR periods, balance transfers, or additional charges added to the card during payoff.