Credit Card Payoff Calculator

A credit card payoff calculator works out how long it will take to clear a credit card balance, the total interest paid, and the minimum monthly payment required to pay off the debt by a target date. It is used by people with outstanding credit card balances who want to understand the true cost of their debt and create a realistic repayment plan.

How to Use the Credit Card Payoff Calculator

1. Enter the current outstanding balance on your credit card.
2. Enter the annual interest rate (APR) on the card.
3. Choose one of two modes: enter a monthly payment to find the payoff date and total interest, or enter a target payoff date to find the required monthly payment.
4. Click calculate to see the months to payoff, total interest paid, and total amount repaid.

The Formula

Months to payoff given a monthly payment M:

n = -ln(1 - (P x r) / M) / ln(1 + r)

Where P is the outstanding balance, r is the monthly interest rate (APR / 12 / 100), and M is the monthly payment. M must be greater than P x r (the monthly interest charge) otherwise the balance never decreases.

Monthly interest charge = Outstanding balance x (APR / 12 / 100)

Minimum payment on most UK credit cards: typically 1 to 2% of the balance or a minimum of £25, whichever is greater.

Real-World Example

Credit card balance: £3,500. APR: 24.9%. Target: pay off in 24 months.

Monthly rate: 24.9% / 12 / 100 = 0.02075

Monthly payment needed: P x r / (1 - (1 + r)^(-n)) = 3,500 x 0.02075 / (1 - (1.02075)^(-24)) = 72.63 / (1 - 0.6114) = 72.63 / 0.3886 = approximately £187 per month

Total repaid: £187 x 24 = £4,488. Total interest: £988.

If you paid only the minimum (2% of balance, recalculating each month): it would take approximately 23 years to clear the balance and cost over £4,000 in interest. Making a fixed payment of £187 clears the same debt in 24 months and saves approximately £3,000 in interest.

The Minimum Payment Trap

Paying only the minimum due each month is one of the most expensive ways to carry debt. Because the minimum payment is typically a percentage of the current balance, it falls each month as the balance reduces. The interest charged falls more slowly than the principal, meaning the bulk of minimum payments go to servicing interest rather than reducing the debt. On a £3,500 balance at 24.9% APR, the first month's minimum payment of approximately £70 includes £72 in interest; paying £70 actually increases the balance slightly. The balance never clears until the minimum payment rises above the monthly interest charge, which happens very slowly on a percentage-of-balance basis. Committing to a fixed monthly payment, even modestly above the minimum, dramatically shortens the payoff timeline. Paying £100 per month on a £3,500 balance at 24.9% clears the debt in approximately 46 months; paying £200 per month clears it in 20 months.

Frequently Asked Questions

Should I pay off my highest interest card first? The debt avalanche method prioritises the highest-APR balance first (while making minimum payments on others), which minimises total interest paid over time. The debt snowball method clears the smallest balance first regardless of rate, providing psychological wins that motivate continued progress. Mathematically, the avalanche is more efficient; behaviourally, the snowball works better for some people. Choose the method you will actually stick to.

Does paying off a credit card hurt my credit score? Paying off a credit card improves your credit score over time. It reduces your credit utilisation ratio (balance as a proportion of available credit limit), which is a significant factor in most credit scoring models. Closing the account after paying it off can slightly reduce your score in the short term by reducing available credit, but leaving a zero-balance account open avoids this. The long-term benefit of eliminating the debt outweighs any short-term scoring impact.

Can I negotiate a lower interest rate with my credit card provider? Yes. Calling your provider and asking for a rate reduction works more often than many people expect, particularly if you have a history of on-time payments and a good credit score. If the provider won't reduce your rate, consider applying for a 0% balance transfer card to another provider. Transfer the balance and clear as much as possible during the 0% introductory period. Be aware of balance transfer fees (typically 2 to 3%) and what rate applies after the promotional period ends.

How does making two payments per month affect payoff time? Paying half your monthly payment every two weeks (biweekly payments) results in 26 half-payments per year, equivalent to 13 full monthly payments. This reduces the average daily balance slightly because the second payment hits the account before the end of the month, reducing the interest charged that month. Over time, this approach shaves a small amount off the payoff timeline and total interest. The effect is more significant for mortgages and large loans than for smaller credit card balances.

Also try these free tools:

• Debt Payoff Calculator
• Credit Card Calculator
• Budget Calculator

A second balance worked to a fixed payment

The 3,500 pound example above is small enough to check by hand. A larger balance shows how much of each payment goes to interest in the early months, and why the first year of a repayment plan moves the balance less than the payment schedule suggests.

Take a balance of 6,200 pounds at an APR of 19.9 percent with a fixed payment of 250 pounds a month. The monthly rate is 19.9 divided by 12 divided by 100, which is 0.01658333.

• Interest in month one: 6,200 times 0.01658333 = 102.82 pounds.
• Of the 250 pound payment, 102.82 pounds services interest and 147.18 pounds reduces the balance.
• The formula gives a term of 32.2108 months, so 32 payments of 250 pounds are needed plus a smaller final payment.
• Applied month by month, the balance clears after 33 months, with 8,000 pounds paid in full monthly payments and a final payment of 53.05 pounds.
• Total repaid: 8,053.05 pounds. Total interest: 1,853.05 pounds.

The share of the first payment that goes to interest is 41.13 percent, and only the remaining 58.87 percent does any work on the debt. Twelve months in, the balance stands at 4,263.46 pounds, which is a reduction of 1,936.54 pounds against 3,000 pounds paid in. The gap between those two figures is the interest for the year.

How the monthly payment changes the outcome

The balance and the rate are fixed in this table at 6,200 pounds and 19.9 percent. Only the monthly payment moves. Each row applies the interest charge first and the payment second, month by month, until the balance reaches zero.

Doubling the payment from 200 to 400 pounds cuts the term from 44 months to 19 and the interest from 2,576 pounds to 1,026 pounds. It does not halve either. The relationship is not proportional in either direction, because a payment that arrives sooner removes interest that would otherwise have compounded against the remaining balance. That is also why the last row of the table still pays 1,026 pounds of interest on a 6,200 pound debt: the rate, not the payment size, sets the floor.

What a percentage minimum payment really does

A minimum payment set as a percentage of the outstanding balance has a property that is easy to miss. The percentage falls with the balance at exactly the same rate, while the interest charge is also a percentage of the balance, and the two percentages do not move in step. The table runs four common minimum rules against the same 6,200 pound balance at 19.9 percent, alongside the fixed 250 pound payment for comparison.

The 1 percent rule does not repay anything. One percent of 6,200 pounds is 62 pounds, the monthly interest at that moment is 102.82 pounds, and a payment smaller than the interest leaves the balance higher at the end of the month. The percentage then applies to a larger balance, the gap widens, and the debt never clears on that rule alone.

The 2 percent rule does clear, in 48 years, and it costs 25,461.59 pounds in interest on a 6,200 pound balance. The same money paid as a fixed 250 pounds a month clears the debt in under three years and costs 1,853.05 pounds. The difference between those two outcomes is 23,608.54 pounds, and it comes from the payment rule rather than from the interest rate. The same effect shows on the 3,500 pound example above: the first month's minimum of 70 pounds is 2.62 pounds short of the 72.62 pound interest charge, so paying only the minimum makes that balance grow. Under a straight percentage rule at 24.9 percent, a 2 percent minimum never clears the debt at all.

Working back from a payoff date

The second mode on the calculator takes a target date and returns the payment. For the 6,200 pound balance at 19.9 percent, the required payment is the balance times the monthly rate divided by one minus, in brackets, one plus the monthly rate raised to the power of negative n, where n is the number of months.

Compressing the term from 36 months to 12 raises the monthly payment by 343.94 pounds and saves 1,395.09 pounds of interest. The saving is real but it is smaller than the extra cash flow suggests, because the shorter term leaves less time for compounding to run and the monthly payment in the 36-month plan still clears the interest comfortably.

The same balance at other payments

The 3,500 pound balance at 24.9 percent is the example used above, and it is worth running at several payment levels, because the term falls faster than the payment rises at the start.

Each row applies the interest charge first and the payment second, and the final payment is the remaining balance, which is smaller than the monthly figure. Twenty four equal payments of 187 pounds total 4,488 pounds, so the month-by-month total in that row sits 11.52 pounds lower once the last payment is reduced. Periods computed by dividing the balance by the payment without compounding the interest come out short of these figures, and the shortfall grows with the term.

What the repayment figures assume

Six assumptions sit behind the tables above.

• Interest is charged once a month at the APR divided by 12. UK cards often quote a monthly rate as well, and APR divided by 12 matches the formula used here. A rate quoted as a monthly percentage is the cleaner input.
• The payment is applied at the end of each month, after the interest for that month has been added.
• No new spending, fees, charges, or balance transfers take place, and the rate does not change. Any of those resets the calculation.
• The starting figure is the balance on the day the repayment plan begins, not an average balance across the month.
• The final payment is whatever remains, so it is normally smaller than the monthly payment.
• Interest is compounded monthly rather than accrued daily. Daily accrual on the same balance produces slightly different totals, and it is the method most card issuers actually use.

The minimum-payment rows model a straight percentage of the outstanding balance with a cash floor. Card terms vary, and many set the minimum as interest plus a percentage of the principal, which behaves differently from a straight percentage. Read the terms on the account before treating any minimum rule here as the one in force.

The formula and the published guidance

The relationship used on this page is the present value of an annuity, the standard fixed-rate amortising loan formula, and it is the same one that prices a repayment mortgage. In the United Kingdom, the Money and Pensions Service publishes consumer guidance on minimum payments and the cost of carrying a balance at moneyhelper.org.uk, and the exact minimum formula for any account is set out in the card terms.