How credit card payoff is calculated
Every credit card charges interest on your remaining balance based on its annual percentage rate, or APR. That yearly rate is divided by 12 to get a monthly rate, and each billing cycle your issuer applies that rate to whatever balance you're carrying. If you pay only part of your balance, the rest keeps accruing interest the following month — which is exactly why credit card debt can feel like it never shrinks even when you're making payments.
This calculator simulates that process month by month. It starts with your current balance, calculates the interest for that month, subtracts your payment (minus the interest) from the principal, and repeats until your balance reaches zero. The result is your true payoff date — not a rough guess, but a month-by-month projection built on the same math your card issuer uses.
A worked example
Say you have a $5,000 balance at a 24.99% APR, and you commit to paying $200 per month. In month one, your card charges about $104 in interest ($5,000 × 24.99% ÷ 12), so $96 of your $200 payment goes toward the principal, leaving a balance of $4,904. As your balance shrinks each month, less of your payment goes to interest and more goes to principal — this is why the last few months of paying off a card feel much faster than the first few. At this pace, it takes roughly 32 months (about 2 years and 8 months) to pay off the card, and you'll pay around $1,460 in total interest.
Why extra payments matter so much
Because interest is calculated on your current balance every single month, even a small increase in your payment compounds into meaningful savings — both in time and in dollars. Paying $250 instead of $200 on that same $5,000 balance cuts your payoff time by roughly 8 months and saves several hundred dollars in interest. Use the Extra Payment Calculator to see the exact impact of any payment increase on your own balance.
Tips to pay off your card faster
- Pay more than the minimum whenever you can — even $20–$50 extra per month adds up quickly on high-APR balances.
- Check whether a balance transfer to a lower or 0% intro APR card would reduce your total interest, factoring in the transfer fee.
- If you have multiple cards, compare the debt avalanche and debt snowball strategies to find the one that keeps you motivated and saves the most interest.
- Avoid adding new purchases to a card you're actively paying down — new charges reset the clock on how quickly you clear the balance.