How to Use This Calculator
- 1
Choose your question
Use the toggle at the top. “By monthly payment” answers “how long will this take?” given what you can afford; “By payoff time” answers “what must I pay?” to hit a target date.
- 2
Enter your balance and APR
Both are on your latest statement. If you carry balances on several cards, run each one separately — APRs often differ by 10 points or more between cards.
- 3
Set your payment or your deadline
In the first mode, enter the fixed amount you'll pay each month. In the second, enter the number of months you want the debt gone in, such as 24 for two years.
- 4
Watch for the warning
If your payment doesn't even cover the monthly interest, the calculator flags it and shows the minimum needed to make any progress at all.
- 5
Stress-test a bigger payment
Nudge the payment up $50 and note how many months disappear. On high-APR debt, small increases have an outsized effect because they all hit principal.
How It Works
Credit card interest is charged on whatever balance remains, month after month. Each billing cycle your balance grows by one-twelfth of the APR, then your payment is subtracted:
The calculator repeats this step until the balance hits zero, counting the months and adding up the interest as it goes. This is also why minimum payments are such a trap: a typical minimum is only 1–2% of the balance plus interest, barely more than the interest charge itself, so almost nothing touches the principal. The debt shrinks at a crawl while the interest meter keeps running. Any fixed payment meaningfully above the monthly interest breaks that cycle, because every payment then bites deeper into the principal than the last one did.
Worked example
Suppose you owe $5,000 at 22% APR and commit to $200 a month. The monthly rate is 0.22 ÷ 12 ≈ 1.833%, so the first month adds about $91.67 in interest and your payment clears only $108.33 of principal.
Repeating that cycle, you reach zero in about 34 months — 2 years and 10 months — after paying roughly $1,750 in interest, about $6,750 in total.
Raise the payment to $300 and the same debt is gone in 21 months with about $1,022 in interest — roughly $730 kept in your pocket.
Frequently Asked Questions
How is credit card interest actually calculated?
Most issuers use a daily periodic rate: your APR divided by 365, applied to your average daily balance each billing cycle. At 22% APR, that's about 0.0603% per day, or roughly 1.83% per month on whatever you owe. Interest is typically only charged if you carry a balance past the due date — pay the full statement balance every month and the grace period means you pay 0%.
What happens if I only make minimum payments?
You stay in debt for a very long time. On a $5,000 balance at 22% APR, a typical minimum of interest plus 1% of the balance starts around $142 and shrinks as the balance drops — stretching the payoff past 20 years and costing over $7,000 in interest. Federal rules require your statement to show this math, so check the minimum-payment warning box on your bill for your own numbers.
Should I use the avalanche or snowball method for multiple cards?
Avalanche means attacking the highest-APR card first while paying minimums on the rest; it's mathematically optimal and saves the most interest. Snowball targets the smallest balance first to score quick wins, which many people find easier to stick with. Studies suggest the motivational boost of snowball helps completion rates, but if the APR gap between your cards is wide — say 29% versus 17% — avalanche can save hundreds.
Will paying off my credit card improve my credit score?
Almost certainly. Credit utilization — the share of your limits you're using — drives about 30% of a FICO score, and scores respond quickly once lower balances are reported. Dropping a maxed-out $5,000 card to zero can add 50 points or more within a cycle or two. Keep the paid-off card open, though: closing it shrinks your available credit and average account age, which can undo part of the gain.
Is a 0% balance transfer card worth it?
Often, yes — if you're disciplined. Transfer offers commonly give 12 to 21 months at 0% APR for a one-time fee of 3–5% of the amount moved. Moving $5,000 costs about $150–$250 upfront but can save well over $1,000 versus paying 22% interest. The catch: the promo rate expires, and new purchases may not get the 0% rate. Divide the balance by the promo months and pay that amount on autopilot.
Should I build savings or pay off my credit card first?
Do a little of both, weighted toward the debt. A starter emergency fund of $1,000 or so keeps a surprise car repair from going straight back on the card. After that, prioritize the card: no savings account pays anywhere near the 20%+ your card charges, so every extra dollar toward the balance earns a guaranteed return no investment can match. Once the card hits zero, redirect the whole payment into savings.