Credit card payoff is the two-number answer to one question: how many months until this balance hits zero, and how much interest will I have paid along the way? Unlike a loan with a fixed schedule, a card balance accrues interest on whatever is still owed each month, so the payoff is built up month by month, not read off a single formula. For a $5,000 balance at a 19.99% APR, paying $250 a month, the balance clears in 25 months and the interest comes to $1,132.29 - $6,132.29 paid in total. You can run any balance, rate, and payment yourself in the credit card payoff calculator, which returns the months to payoff, the total interest, the payoff date, and a month-by-month schedule.
How the Payoff Calculation Works, Month by Month
The engine is simple even though the result is not obvious. Each month the card charges interest equal to the balance times the monthly rate, and the monthly rate is the annual APR divided by 12. A 19.99% APR is 19.99 / 12, about 1.67%, charged every month on whatever you still owe. Your payment then comes out of the top of that balance: the part of the payment that exceeds the month's interest is what actually shrinks the debt, and the rest just covers the new interest. If you want to untangle what an APR really is, and how it relates to the APY you might be quoted, the APY / APR converter does that.
Because the interest is charged on the balance before your payment lands, the early payments are heavily weighted toward interest. That is the defining feature of card payoff, and it is why the total interest runs so much larger than a quick "rate times balance" estimate would suggest.
A Worked Example: $5,000 at 19.99%, Paying $250 a Month
Run the numbers for a $5,000 balance at 19.99% with a $250 monthly payment. In month one the card charges $5,000 times 1.67%, which is $83.29 of interest. Of your $250 payment, $83.29 goes to that interest and only $166.71 reduces the balance, which drops from $5,000 to $4,833.29. As the balance falls, each payment's interest share shrinks and more of it becomes principal. By the final month, number 25, the last payment is just $132.29, of which only $2.17 is interest.
Add it up and the payoff takes 25 months, the total interest is $1,132.29, and the total you pay is $6,132.29 - more than $1,000 above the balance you started with. The skew is concentrated up front: $805.64 of that interest, about 71%, is paid in the first twelve months, while the last year barely adds any. The monthly rate, APR divided by 12, is just compounding applied on a monthly clock, and the companion article on compound interest shows exactly how that clock compounds.
The Minimum-Payment Trap
Here is the case that should change how you think about the number. The calculator models the typical minimum as 2% of the balance, with a $10 floor. Pay only that minimum on $5,000 at 19.99% and the balance never reaches zero. The 2% minimum is bigger than the 1.67% monthly interest, so the balance does shrink - but by only about 0.33% a month, which is glacial. After 50 years of minimum payments you would still owe roughly $549, and the interest alone would have run past $20,000. The minimum keeps the account current and the credit report clean, which is precisely why it is so easy to keep paying and so hard to escape.
When You Owe More Than One Card: Snowball vs. Avalanche
A single balance is one payoff problem. The moment you have several cards, it becomes a sequencing problem: which debt do you attack while the others sit and accrue? The two standard strategies are the debt snowball, which pays the smallest balance first for quick, confidence-building wins, and the debt avalanche, which pays the highest APR first to minimize total interest. Both run the exact same month-by-month math on the active debt. The debt snowball calculator lays out the order and the timeline for either strategy across multiple balances.
What the Interest Is Really Costing You, and the Money You Free Up
The $1,132.29 is the price of borrowing that $5,000, and the one lever you control is the size of the payment. Adding just $100 a month, for a $350 total, cuts the payoff from 25 months to 17 and saves $373.96 in interest; adding $200, for $450 a month, gets you to 13 months and $575.96 of interest. The savings are non-linear and front-loaded, because every extra dollar hits a high balance where it retires the most interest.
The payoff also flips the direction of the money. The $250 a month you were paying the card becomes free cash, and what that cash can earn if you invest it, compounded, is exactly what the compound interest calculator models. For the fast mental check on how quickly that freed payment grows, the rule of 72 calculator turns a rate into a doubling time.
After Payoff: Do Not Run the Balance Back Up
The reason most people charge the card back up is a missing buffer: a small unexpected expense sends them straight back to revolving at the same 19.99% rate. The move that sticks is to redirect the payment you just freed into a cushion before spending it, so the card can sit at zero. The emergency fund calculator sizes that buffer, and the net worth calculator lets you watch the payoff show up as your net worth climbs.