Debt Payoff Calculator — Snowball vs Avalanche
Enter your debts and extra monthly payment to see your real payoff timeline and total interest — compared side by side for both the snowball and avalanche strategies.
Your debts
Works in any currency — just keep units consistent. Leave a row blank to skip it.
Avalanche saves 278 in interest vs. snowball on these numbers, though snowball can still be the better choice if staying motivated matters more to you than the lowest total cost.
Payoff order (avalanche)
- 1.Credit card
- 2.Personal loan
- 3.Car loan
How this is calculated
This runs a real month-by-month amortization simulation, not a rough estimate: each month, interest accrues on every remaining balance, minimum payments are applied to all debts, and any extra payment goes toward whichever debt your chosen strategy prioritizes. As each debt is paid off, its minimum payment rolls into the extra amount for the next debt — the actual mechanism behind both the snowball and avalanche methods, sometimes called the 'debt snowball effect'.
Avalanche orders debts by highest interest rate first. Mathematically, it minimizes total interest paid, since you stop the fastest-growing balance from accruing interest as early as possible.
Snowball orders debts by smallest balance first. It usually costs a little more in total interest than avalanche, but clears individual debts faster, which behavioral-finance research on debt repayment has found helps some people stick with the plan.
This calculator shows both, side by side, so you can see the actual size of the trade-off for your own numbers rather than picking a method on faith.
This tool provides an estimate for informational purposes based on the figures you enter and isn't financial advice.
Frequently asked questions
Which method should I use, snowball or avalanche?
Avalanche saves more money in interest — always, or ties, mathematically. Snowball can still be the better real-world choice if quick wins keep you motivated to stay on the plan; this calculator shows you exactly how much that motivation costs in extra interest, so you can decide with real numbers.
Why does the payoff order matter if the extra payment amount is the same either way?
Because the extra payment isn't just applied flat across debts — it's concentrated on one debt at a time, in the order your strategy picks. Which debt gets paid off first (and how much interest it accrues in the meantime) changes the total interest bill.
What if my minimum payments don't cover the interest?
If a debt's APR is high enough that the minimum payment barely covers (or doesn't cover) the monthly interest, the balance can shrink very slowly or not at all without extra payments — the calculator will flag this so you know extra payments aren't optional on that debt.
Sources
- Behavioral research on debt repayment strategies and small-balance-first motivation (e.g. Kellogg School of Management, 'Dynamics of Consumer Debt')
Last updated 2026-10-30.