Credit Card Payoff Calculator

See how long a card takes to clear and the interest it costs.

How the Math Works

The formula n = −ln(1 − rB/PMT) ÷ ln(1+r) calculates the number of payments (n) needed to pay off a credit card balance. Here, B is the initial balance, r is the monthly interest rate (APR divided by 12), PMT is the fixed monthly payment, and ln is the natural logarithm. The equation balances the present value of the debt against the present value of the payments, using logarithms to isolate n. The term (1 − rB/PMT) represents the remaining balance after interest is applied, and taking the negative logarithm adjusts for compounding, while dividing by ln(1+r) accounts for monthly interest accumulation. This ensures the payment schedule fully amortizes the debt over time.

Practical Applications

To use the calculator, input your current credit card balance (B), the annual percentage rate (APR), and the fixed monthly payment amount (PMT). For example, with a $5,000 balance, 18% APR (0.015 monthly rate), and $200 monthly payments, the formula computes how many months it will take to eliminate the debt. Adjust PMT to see how increasing payments shortens the payoff period or explore scenarios like lower APRs via balance transfers. The tool helps model different payment strategies to minimize total interest paid and prioritize debt reduction.

Day-to-Day Use

This calculator empowers you to take control of credit card debt by visualizing repayment timelines, enabling smarter budgeting and payment planning. By knowing exactly how long it takes to pay off a balance, you can prioritize high-interest debts, adjust spending habits, or negotiate payment plans with creditors. It also highlights the financial impact of compounding interest, motivating faster repayment to save money and reduce stress. Whether you're consolidating debt or starting a repayment plan, this tool transforms abstract debt into actionable steps toward financial freedom.

Worked example

$5,000 at 20% APR, $200/mo → ~32 months.

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