How this calculator works
Each month the card charges interest of APR ÷ 12 on the balance, then your payment is subtracted. The calculator repeats this until the balance reaches zero. In target-date mode it uses the loan payment formula to find the fixed payment that clears the balance in the chosen number of months.
Monthly interest = Balance × APR ÷ 12
Months (fixed payment) = −ln(1 − r × B ÷ P) ÷ ln(1 + r)
Payment (target) = B × r ÷ (1 − (1 + r)^−n)
Worked example
Using the default values in the calculator above:
| Input | Value |
|---|---|
| What do you want to find? | Time to pay off at my payment |
| Card balance | $6,000 |
| Card APR | 22.9 % |
| Monthly payment | $250 |
| Result | Value |
|---|---|
| Months to pay off | 33 months |
| Total interest | $2,101 |
| Debt-free in | 2 yr 9 mo |
| Total paid | $8,101 |
| Interest in the first month | $114.5 |
Step by step:
- First month interest = $6,000 × 1.9083% = $114.5
- So $135.5 of your first $250 payment reduces the balance
- Repeat each month (interest on the new balance, then subtract the payment) until the balance is zero
Paying off $5,000 at 22% APR
Months and total interest at different fixed monthly payments.
| Monthly payment | Months to pay off | Total interest |
|---|---|---|
| $125 | 73 months | $4,095 |
| $150 | 52 months | $2,798 |
| $200 | 34 months | $1,750 |
| $250 | 26 months | $1,286 |
| $300 | 21 months | $1,022 |
| $400 | 15 months | $732 |
| $500 | 12 months | $574 |
Common mistakes to avoid
- Paying only the minimum — it is set so the balance shrinks very slowly.
- Moving debt to a 0% card without a plan to clear it before the promo ends.
Frequently asked questions
How long does it take to pay off $6,000 at 22.9% with $250 a month?
About 33 months, with roughly $2,100 of interest.
Should I pay off the highest APR card first?
Paying the highest-APR balance first (the avalanche method) costs the least interest; paying the smallest balance first (snowball) gives quicker wins. Both work if you keep paying.