How long will your credit card take to pay off?
A $3,500 store card at 28%, paid at $150 a month, takes 35 months to clear and costs $1,613 in interest: $5,113 in all.
The worked example
A store card with a $3,500 balance at 28% APR, paid at a fixed $150 every month until it is gone, with nothing new charged to it.
| You put in | |
|---|---|
| Balance | $3,500 |
| APR | 28% |
| Monthly payment | $150 |
| The math says | |
| Monthly interest rate | 2.33% |
| First month’s interest | $82 |
| Reaches the balance in month one | $68 |
| Time to pay off | 35 months (about 2.9 years) |
| Total interest | $1,613 |
| Total paid | $5,113 |
Every figure on this page is computed from these inputs by the same calculator the channel’s Shorts use. The same example and figures were used in a Short published September 30, 2026.
Run your own numbers
The calculator starts at the worked example. Change any figure to see yours.
Time to pay off
35 months (about 2.9 years)
Total interest
$1,613
Total paid
$5,113
Educational content, not financial advice.
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Your next moves
Use your statement’s exact APR
The payoff date moves with every point of APR, so a guess can be months out.
Try a fixed extra amount
See what a steady extra each month does to the date and the interest.
Extra payment
How the math works
Every month the card charges interest on whatever you still owe. 28% a year works out to 2.33% a month, so on $3,500 the first month’s interest is $82. Your $150 payment covers that interest first, and only the remaining $68 reaches the balance.
Next month the balance is a little smaller, so the interest is a little smaller and a little more of the same payment goes to the balance. Repeat that until nothing is left and you have the whole payoff: 35 months, about 2.9 years, with $1,613 of interest along the way. That is $5,113 to clear a $3,500 balance.
What people get wrong
The usual mistake is judging a card by its balance. What decides the cost is the rate and how much of each payment is left once the interest is paid. A payment that only just beats the interest can run for years, even on a modest balance.
The other mistake is treating the payment as fixed. Anything above it skips the interest and comes straight off the balance, which lowers every month of interest after it. Adding $50 a month to this card clears it 12 months sooner and saves $562.
A third is reading the statement balance as the cost. The balance is what you owe today; the cost is the balance plus the interest still to come, $1,613 here if the payment stays at $150. That second number is the one your payment decides.
How to read the result
Start with the time to pay off, then the total interest. Together they tell you what the card costs over its whole life, not just this month. If either one looks too high, the payment is the lever you control: the balance and the rate are already set.
If the calculator says “never”, the payment does not cover the monthly interest, so the balance can only grow, and the fix is a bigger payment. Otherwise, put in the balance, APR and payment from your own statement, then try an extra amount and watch how many months it removes.
Questions
How is credit card interest worked out each month?
This calculator divides the APR by twelve and charges that rate on the balance each month: at 28%, 2.33% a month, or $82 on $3,500 in the first month. Card issuers usually work interest out daily on your average balance, which comes to nearly the same.
How much faster is it if I pay more each month?
On this card, $50 more a month, $200 in all, clears it in 23 months instead of 35 months and saves $562 in interest.
Why does the calculator say my card will never be paid off?
Because the payment does not cover the interest charged each month, so the balance never falls. On $3,500 at 28%, that happens when the payment is no bigger than the first month’s interest of about $82.
Does this work for a loan as well as a card?
For any balance paid down with the same amount each month, yes: the math is the same. A loan with a fixed term works the other way round, with the payment set by the term, and the loan cost page covers that.
Interest compounds monthly at APR ÷ 12 and each payment lands at the end of the month, after that month’s interest. The payment stays the same every month and nothing new is charged to the card. Disclaimer