Debt Payoff Calculator

Compare snowball and avalanche strategies across multiple debts.

%
Debt-free in
3 yr 5 mo

paying $500.00/month

Total interest
$5,076.99
Total paid
$20,076.99
With +$100.00/mo
32 months
Interest saved
$1,136.19
Show the working
  1. 1At $500.00/month it takes 40.2 months
  2. 2Adding $100.00/month saves $1,136.19 and 9 months
Formula
months = −ln(1 − rB ÷ P) ÷ ln(1 + r)

How it works

How long a debt takes to clear at a fixed monthly payment, and how much an extra amount each month saves in time and interest.

Example

$15,000 at 18% paying $500/month clears in about 3 years 4 months; an extra $100/month saves roughly 8 months.

About the Debt Payoff Calculator

Compare snowball and avalanche strategies across multiple debts. It sits in the Finance & Loans section of NWS Calc, a free collection of calculators that run entirely in your browser. There is no signup, no paywall and no tracking — open the page, enter your numbers, get an answer.

Frequently asked questions

Is the Debt Payoff Calculator free to use?
Yes. Every calculator on NWS Calc is completely free, with no signup, no usage limits and no ads.
Does my data leave my device?
No. The Debt Payoff Calculator runs entirely in your browser using JavaScript. Nothing you type is uploaded, logged or stored on a server.
Can I use the Debt Payoff Calculator on my phone?
Yes. The page is fully responsive and works in any modern mobile or desktop browser — there is nothing to install.
What else is in Finance & Loans?
Loans, mortgages, interest, savings and investment returns. You can browse the full Finance & Loans category for related calculators.

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