Debt Payoff Calculator
When you’ll be debt-free, and whether snowball or avalanche gets you there cheaper.
Good to know. The best method is mostly the one you keep going with. The math is close more often than not.
Not financial advice. Uses only the numbers and rates you enter — no live data.
How it works
In plain words
Each month every debt adds its interest and gets its minimum payment. Everything else in the budget, the extra and the minimums of debts already paid off, goes to one debt at a time: the highest rate first (avalanche) or the smallest balance first (snowball). The budget stays the same until the last debt is gone.
The formula
Budget = the minimums + the extra Each month: balance = balance × (1 + rate ÷ 12) − payment Avalanche order: rate, highest first Snowball order: balance, smallest first
Worked example
Three debts of 6,000 at 24%, 2,000 at 7% and 9,000 at 10%, with 300 a month on top of the minimums: the avalanche clears them in 25 months with 2,383.03 of interest. The snowball takes 26 months and 2,750.29.
Sources
- Brealey, Myers and Allen, Principles of Corporate Finance, chapter 2 The standard formulas for loan payments, compounding and present value, the same as a spreadsheet’s PMT and FV.
Sources checked September 29, 2026. 8 automated tests check its answers on every change.
About the debt payoff calculator
With more than one debt, the question is where the extra money goes. Both popular methods agree on the basics: pay the minimum on everything, put every spare amount on one debt, and when it is gone, roll its payment into the next. They differ only in which debt comes first.
The avalanche goes after the highest interest rate first. It is the cheapest order: each extra payment stops the most expensive interest. The snowball goes after the smallest balance first. It usually costs a little more, but the first debt disappears sooner, and many people find that quick win keeps them going.
This calculator runs both, so you can see what the difference really is for your debts. Often it is small, and staying with the plan matters far more than which plan it is. When one debt has a much higher rate, such as a credit card next to a car loan, the avalanche can save a real amount.
Keep the monthly budget the same as debts are cleared, even as minimums on cards fall. That rollover is what makes both methods fast. Keep a small emergency fund alongside, so a surprise bill doesn’t go straight back on a card.
Questions people ask
Snowball or avalanche: which is better?
The avalanche (highest rate first) costs the least interest, or the same. The snowball (smallest balance first) clears a debt sooner, which helps many people stick with it. For many debts the difference is small.
What is the debt snowball method?
Pay the minimum on all debts and everything extra on the smallest balance. When it is gone, add its payment to the next smallest, and so on.
What is the debt avalanche method?
The same, but the extra goes to the debt with the highest interest rate first, then the next highest.
I have more than three debts. What do I do?
Combine similar ones: add up the balances and minimums of debts with about the same rate, and use their average rate.