Last updated October 10, 2026 · Report an error
Before juggling multiple debts with a snowball or avalanche strategy, it helps to answer the simplest question first: at your current payment, how long will it take to pay off just one debt, and how much will the interest cost you? This calculator answers exactly that.
Give it a starting balance, an annual interest rate, and a fixed monthly payment, and it simulates the payoff month by month.
How it works
Enter the current balance, the annual interest rate, and the fixed monthly payment you plan to make. The calculator applies interest to the remaining balance each month, subtracts your payment, and repeats until the balance reaches zero — reporting the number of months, an approximate payoff date, and the total interest paid.
- Enter current balance.
- Enter annual interest rate (%).
- Enter monthly payment.
- Click Calculate to see your results.
Examples
A credit card balance
A $5,000 balance at 19.99% APR, paid at $200/month, takes 33 months to pay off and costs about $1,521 in total interest.
Who should use it
- Checking how long a single credit card or loan balance will take to pay off.
- Testing how a larger monthly payment shortens the payoff time and reduces interest.
Industry applications
- Personal finance and budgeting
- Financial counseling and coaching
Advantages
- Gives an exact months-to-payoff and total interest for a single debt.
- Warns you if a payment is too low to ever pay off the balance.
- No account, subscription or watermark.
Limitations
- Assumes a fixed interest rate and fixed payment for the whole payoff period.
Common mistakes to avoid
- Entering a payment that barely covers the monthly interest, resulting in an extremely long or impossible payoff timeline.
- Forgetting that a variable-rate debt's actual payoff time will differ if the rate changes.
Best practices
- Increase your monthly payment even slightly to see how much faster the debt disappears and how much interest you save.
- Use the Debt Snowball or Debt Avalanche calculators once you're ready to plan multiple debts together.
Tips
- Even a small increase in monthly payment can meaningfully shorten the payoff time on high-interest debt.
- Once you're juggling more than one debt, move to the Debt Snowball or Debt Avalanche calculators for a combined payoff plan.