The Planned Life

Debt Payoff Calculator

Free debt payoff calculator: see how many months to clear a balance, the total interest you'll pay, and how much an extra payment saves you.

The balance, the rate and what you pay

Enter a balance, its rate and what you pay each month to see how long it takes and what the interest costs.

Runs entirely in your browser. Your numbers are saved only on this device (localStorage) — never uploaded.

How this is calculated

  • monthly rate = APR / 12
  • each month: interest = balance x monthly rate; balance = balance + interest - payment
  • repeat until the balance reaches zero; count the months

What it assumes

  • Interest compounds monthly on the remaining balance, which is how most cards work.
  • The payment is the same every month and nothing new is charged to the account.
  • If the payment is smaller than one month's interest, the balance never clears and the tool says so instead of returning a number.
  • Fees, promotional rates and minimum-payment rules are not modelled.

Worked example

In: $2,000 balance at 19.99% APR, paying $100 a month
Out: 25 months and $452.92 in interest. Adding $50 a month: 16 months and $280.66 - it saves $172.26 and nine months

If a result here disagrees with your own arithmetic, that is worth reporting — tell me and include your numbers.

Build the budget that frees up those paymentsThe free Monthly Budget Starter gives you a zero-based plan so you can find extra to throw at debt. Get the free budget template →