Ask anyone carrying a credit card balance what they owe and they can usually tell you. Ask when it will be gone and almost nobody can — because the answer depends on a race between your payment and the interest, and interest does not advertise its pace. Take the balance this calculator opens with: $6,500 at 24% APR, paid at $200 a month. That debt is gone in 54 months — 4 years and 6 months — and it costs $4,300 of interest on the way out, for $10,800 paid in total. Add $100 a month and the same debt dies in 29 months with $2,200 of interest. This page shows the math behind those numbers, and why the minimum payment printed on your statement is the most expensive option on it.

The one rule: beat the interest.

Every payoff plan obeys a single rule: your payment must exceed the interest your balance charges each month, or the balance never falls. The first month's interest is the balance times the monthly rate — the APR divided by 12. On $6,500 at 24%, that is $6,500 × 2% = $130 a month. Pay exactly $130 and you are renting the debt forever: the balance at the end of the month is the balance at the start. Pay less and it grows. The damage near the line is quieter but real. Pay $150 a month on that same debt — a payment that sounds respectable — and only $20 of the first payment touches principal. The calculator's verdict: 102 months, eight and a half years, $15,300 paid, and $8,800 of interest, more than double the $4,300 the same debt costs at $200 a month. Nothing about the card changed; only the distance between the payment and the $130 line did. That is why the first field to play with on this page is not the extra payment — it is the gap between your payment and your first month's interest.

The worked example, and what $100 extra really does.

At $200 a month, the $6,500 balance at 24% APR takes 54 months and $4,300 of interest. Now add $100 of extra payment, for $300 a month total. Every dollar of that extra goes straight to principal — there is no interest charged on money you have already repaid — so the balance falls faster, which lowers next month's interest, which sends even more of the payment to principal. The result is not 20 percent better for 50 percent more money; it is 25 months sooner and $2,100 less interest: debt-free in 29 months at $8,700 total. The pattern holds at other sizes. A $12,000 balance at 19.99% APR paid at $350 a month takes 52 months and $6,200 of interest; add $150 extra and it ends in 31 months with $3,500 of interest — 21 months and $2,700 saved. Two honest notes about how these figures are produced: the calculator rounds the payoff up to whole months and counts the last payment as a full one, so your real final payment will be smaller and the true interest a little lower than shown; and it holds the APR constant, so if your rate resets, re-run the numbers.

Why the minimum payment is designed to stretch.

Your statement's minimum is not a payoff plan; it is the smallest amount that keeps the account current, and it is usually calculated as the month's interest plus about 1 percent of the balance (some issuers use a small flat percentage of the balance instead). Because it is a percentage of a shrinking balance, the minimum shrinks every month — which feels kind and is anything but. Run the default debt on minimums alone, under that common interest-plus-1-percent formula: the first minimum is $195, close to the $200 fixed payment above, yet the debt takes 260 months — 21 years and 8 months — and $11,886.92 of interest to die, against 54 months and $4,300 at a fixed $200. Same debt, same first payment, wildly different ending, purely because one payment holds still and the other retreats. This is why the calculator asks for your payment as a fixed dollar amount: pick the number yourself, hold it steady as the balance falls, and the math above is the math you get.

Avalanche or snowball? The honest answer.

If you have several debts, the order you attack them in has two famous answers. The avalanche method sends every extra dollar to the highest APR first; the snowball method clears the smallest balance first, whatever its rate. Here is the part the arguments usually skip: for a single debt, the two methods are identical — order only exists when there is more than one balance. Across several debts, the avalanche always costs the least interest, by arithmetic: interest accrues fastest on the highest rate, so killing that balance first removes the most expensive dollars. The snowball can cost more — sometimes a little, sometimes a lot, depending on how the rates and balances line up — and in exchange it produces early, visible wins, which is why some people stick with it long after they would have quit an avalanche. The calculator's position is the accountant's one: run your debts one at a time, look at the interest each plan costs, and if the snowball's extra cost is small, the plan you will actually finish beats the plan that is merely optimal. What moves the total most is rarely the order; it is the size of the extra payment and whether it survives the year.

If the payment does not cover the interest.

Sometimes the honest output is the zero this calculator shows when a payment cannot beat the monthly interest — it means the plan, as entered, never ends, and it is better to learn that from a calculator than from five years of statements. The levers, in order of reliability: raise the payment above the interest line by anything at all, because the first dollars past the line are the hardest-working; ask the issuer about a lower APR or a hardship plan, which costs a phone call; or move the balance. A 0% balance-transfer offer makes the interest zero for the promotional window — on $6,500, a typical 3% transfer fee is $195, against $4,300 of interest at $200 a month — but the fee is charged up front, the rate after the promotion is usually high, and any balance left when the window closes goes back to growing. The transfer only wins if your payment clears the balance inside the promotion, which is exactly the calculation at the top of this page, run with the promo rate and the promo deadline as your finish line. If none of the levers reach, a nonprofit credit counselor can negotiate the rates down through a debt management plan — a slower road, but one where the balance actually falls.

Turning the result into a plan.

Read the output in this order: months to pay off, total interest, then the two saved figures. The months tell you the finish date you are actually aiming at; the interest is the price of the road. Then stress-test the plan the way life will: drop the extra payment to zero for a three-month emergency in your head — does the base payment still beat the interest line? If it does, the plan bends instead of breaking. Set the payment on autopay for the fixed amount you chose, not the minimum, because a fixed payment is the entire mechanism — it is what converts a shrinking minimum into a shrinking balance. And when a debt dies, roll its whole payment into the next one rather than spending it; that roll, repeated, is the whole snowball-and-avalanche engine, and it is why the last debt on the list always dies faster than the math on this page suggests. Start with the debt in front of you: enter it, beat its interest line, and give yourself a date.

With the pre-filled defaults — Current Balance $6,500, Interest Rate (APR) 24%, Current Monthly Payment $200, Extra Monthly Payment $0 — the Debt Payoff Calculator returns Total Monthly Payment (with extra) $200.00, Months to Pay Off 54, Payoff Time — Years 4 yrs, Payoff Time — Months 6 mos, Total Amount Paid $10,800.00, Total Interest Paid $4,300.00, Months at Current Payment Only 54, Interest at Current Payment Only $4,300.00, Months Saved by the Extra Payment 0, Interest Saved by the Extra Payment $0.00. Change any input and those results update instantly, so you can see exactly how each number you enter moves the answer.