Browse
Finance
Everyday Math
Home Project
Units
Intelligence Map State metrics Data products API Pricing Trust Center Methodology
Finance

Debt Payoff Calculator

$
%
$
Months to payoff
37
Total interest
$2,870.63
Total paid
$10,870.63

See how long it takes to clear a balance and how much interest you'll pay at a fixed monthly amount.

By Maya R. · Reviewed by David K., CFA · Updated

This is an educational estimate, not financial advice. Figures exclude taxes, fees, and individual circumstances. Verify with a licensed professional before making money decisions.

Advertisement

How to use this calculator

  1. Enter your current balance.
  2. Enter the APR on the card or loan.
  3. Set the fixed monthly payment you can commit to.
  4. See the months to payoff and total interest — raise the payment to shrink both.

Formula

n = −ln(1 − iB/PMT) ÷ ln(1 + i)
  • n — months to payoff
  • B — current balance
  • i — monthly rate (APR ÷ 12)
  • PMT — fixed monthly payment

Worked example

An $8,000 balance at 21% APR with a fixed $300/month is paid off in about 37 months, costing roughly $2,870 in interest. Paying $400 instead clears it in about 25 months.

Frequently asked questions

What if my payment is too low?

If the payment is less than the monthly interest, the balance never falls — increase the payment.

Snowball or avalanche?

Avalanche (highest rate first) saves the most interest; snowball (smallest balance first) builds momentum.

Does this assume no new charges?

Yes — adding new debt extends payoff time.

Is the APR monthly or yearly?

Enter the annual APR; the tool divides by 12 internally.

How can I pay off faster?

Raise the monthly payment or lower the rate via a balance transfer.

Related calculators

Finance Compound Interest Calculator Finance Mortgage Payment Calculator Finance Loan Payment Calculator Finance APR Calculator
MR
Maya R. · Author
Reviewed by David K., CFA · Updated 2026-06-03
Sources
Methodology · Report an error
Embed this calculator
Includes a “Powered by hiinformation” link.
View answer.json (AI feed) 
{
  "tool": "debt-payoff",
  "question": "How does the Debt Payoff Calculator work?",
  "answer": "See how long it takes to clear a balance and how much interest you'll pay at a fixed monthly amount.",
  "formula": "n = −ln(1 − iB/PMT) ÷ ln(1 + i)",
  "inputs": [
    {
      "id": "balance",
      "label": "Balance",
      "unit": "$"
    },
    {
      "id": "rate",
      "label": "APR",
      "unit": "%"
    },
    {
      "id": "payment",
      "label": "Monthly payment",
      "unit": "$"
    }
  ],
  "sources": [
    {
      "name": "CFPB — Paying down debt",
      "url": "https://www.consumerfinance.gov/",
      "note": "Payoff strategies."
    }
  ],
  "updated": "2026-06-03"
}