Guide

Free debt snowball calculator

Snowball Penguin is a free debt snowball calculator that runs in your browser. Type each debt’s balance, minimum payment and interest rate, add what you can spare each month, and it tells you which debt to pay this month, how much to pay, and the month you’re debt-free. No account and no bank connection.

The example (assumptions, not your numbers)
DebtBalanceAPRMinimum
Store card$45027%$50/mo
Medical bill$1,2500%$75/mo
Credit card$4,80024%$150/mo

Plus $300 a month on top of the minimums. Minimums held fixed, interest charged monthly at APR ÷ 12, no new charges. Figures below are the planner’s own math on these numbers, rounded to the dollar. Minimums only means paying each debt just its own minimum, nothing extra; when one is paid off, its minimum stops instead of moving to the next debt.

What it shows on this example

  • Debt-free in: 1 yr 1 mo at $575 a month (vs. 4 yr 3 mo paying only each minimum).
  • First win: Store card, gone in month 2.
  • Interest along the way: about $851, against $2,932 at the minimums.

How the calculator works

Every month it charges each debt its interest (APR ÷ 12), pays every minimum, and puts the extra on the smallest balance. When a debt hits zero, its minimum joins the extra for the next one. It keeps going until every balance is zero.

If you leave a rate blank it assumes 22% and flags it until you fill it in. It also handles 0% promo deadlines and one-time payments like a tax refund.

Free, and what isn’t

The whole planner is free: all three strategies, the monthly check-in, charts, a Google Sheet export and a CSV backup. Pro is optional ($5 a month or $49 once). It keeps a record of every month you check in, prints a PDF of the plan, and syncs it across devices.

Try the calculator with this example

Opens the free planner with this example already typed in. Swap in your own balances, rates and minimums. No signup, no bank connection, and your numbers stay in your browser.

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