Credit Card Payoff Calculator

Guide by Kepler Oates · Updated Oct 22, 2026

What this calculator is for

Credit card debt is easy to carry and hard to see clearly. Statements show a minimum payment, but rarely make plain how long that leaves you in debt or what it costs. This calculator answers one of two questions about a single card:

• How long will it take? Enter your balance, the card's APR and what you pay each month. You get your debt-free time, total interest and total paid.
• What should I pay each month? Enter the balance, APR and the number of months you want to be done in. You get the fixed monthly payment that clears it on time.

Either way, the tool also shows what adding just $50 a month would do: how much sooner you finish and how much interest you save.

How the math works

APR is a yearly rate. The calculator turns it into a monthly rate by dividing by 12 (APR ÷ 100 ÷ 12), then works month by month:

1. Interest for the month = balance × monthly rate.
2. That interest is added to the balance.
3. Your payment comes off.
4. Repeat until the balance reaches zero.

It assumes no new purchases on the card. Card issuers usually charge interest daily, so your real numbers can differ slightly, but the monthly method gives a close planning estimate.

In "What should I pay" mode, the tool uses the standard amortization formula, the same one used for car loans: payment = B × r ÷ (1 − (1 + r)^−n), where B is the balance, r the monthly rate and n the number of months.

The interest-only trap

If your payment is no bigger than one month's interest, the balance never goes down. The tool shows Never and tells you the interest-only amount, so you know the minimum it would take to make progress.

Worked example

Example numbers only: a $5,000 balance at 22% APR, paying $200 a month.

1. Monthly rate: 22 ÷ 100 ÷ 12 = 0.018333.
2. First month's interest: $5,000 × 0.018333 = $91.67.
3. Of your $200, $91.67 goes to interest and $108.33 to the balance, leaving $4,891.67.
4. Repeating this, the card is paid off in 34 months (2 years 10 months).
5. Total interest: about $1,750. Total paid: about $6,750.

Now the $50 test. At $250 a month, the card is clear in 26 months, 8 months sooner, and you save about $464 in interest.

For comparison, at $100 a month, barely above the $91.67 of interest, the same card would take about 11 years 5 months and cost about $8,678 in interest, more than the original balance.

Setting a deadline instead

Switch to "What should I pay each month?" and enter 24 months. Using the formula with B = 5,000, r = 0.018333 and n = 24, the payment is $259.39 a month. Total interest comes to about $1,225, so you pay about $6,225 in all.

How to read your results

• Monthly payment: what you pay, or what you need to pay to hit your deadline.
• Debt-free in: years and months until the balance is zero. The note below gives an approximate month.
• Total interest: the real cost of carrying the balance.
• Total paid: balance plus interest.
• The $50 line: a quick way to see whether a small stretch is worth it. It usually is.

Common mistakes

• Paying only the minimum. Minimums are often set so the balance falls very slowly. Compare your minimum in the tool and see the payoff time.
• Still using the card. The results assume no new purchases. Keep spending on it and the payoff date moves away.
• Entering the wrong rate. Use the purchase APR on your statement. If part of the balance is on a promotional rate, the result will be rough.
• Forgetting when a 0% offer ends. If you have a promotional rate, check the end date and what rate applies after.
• Treating one card in isolation when you have several. This tool handles one balance at a time.

Practical tips

• Set your payment as an automatic, fixed amount rather than "minimum due". As the balance falls, a fixed payment does more work.
• Use "What should I pay" mode to pick a realistic deadline, then automate that amount.
• Put windfalls, refunds or side income straight onto the balance.
• Pause or lower the card's use while you pay it down, so the numbers stay true.
• A small emergency fund stops the next surprise from landing back on the card.

Doing the work

Paying off a card is a long run of small, boring payments, and that is the work. Log each one and watch the balance drop, the same way the workbook's daily Receipt records what you did and what it produced. Got more than one debt? The Debt Payoff Calculator and the guide Debt Snowball vs Avalanche help you choose which to attack first.

This is general information, not financial advice.

Frequently asked questions