Debt Payoff Calculator
List your debts and an extra monthly payment to compare the avalanche and snowball methods — how long each takes and how much interest each costs.
Result
Add your debts to compare payoff plans.
How to use this calculator
- Add each debt with its balance, interest rate and minimum payment.
- Enter how much extra you can pay each month.
- Compare the two plans and the order debts are cleared in.
Formula
Each month, interest (rate ÷ 12) is added to every balance, all minimums are paid, and the extra money goes to the target debt. When a debt is cleared, its minimum rolls into the next target. Avalanche targets the highest interest rate; snowball targets the smallest balance.
Worked example
Two debts
With a 1,000 card at 25% and a 500 loan at 10%, avalanche pays the card first and snowball pays the loan first; avalanche costs less interest.
Assumptions and limitations
- Everything runs in your browser; nothing you enter is uploaded or stored.
- Rates and minimum payments are assumed fixed. Fees and promotional rates are not modelled.
Frequently asked questions
Which method is best?
Avalanche saves the most interest. Snowball can keep you motivated with quick wins. The best plan is the one you will stick to.
What if a minimum payment does not cover the interest?
The balance would grow forever, so the calculator asks you to add an extra payment or check the figures.