Both methods do the same first thing: pay the minimum on every debt, every month, no exceptions. The only question is where the extra money goes. The avalanchesends every extra dollar to the highest-APR debt until it's gone, then to the next-highest, and so on. The snowball sends every extra dollar to the smallest balance instead — ignoring APR entirely — and rolls each cleared payment into the next-smallest once that debt is retired.
What the example above is doing
The card is both the smallest balance and the highest APR, so the two methods agree on month one and clear it at the same time — month 26 either way. That is common: small credit card balances at 20-25% APR are usually the correct first target under either rule.
They part company on debt number two. The avalanche looks at APR and points the freed-up $200 plus the card's old $200 minimum at the student loan (8.5%, $30,000), leaving the car loan to finish on its own amortization schedule at month 60. The snowball looks at balance and attacks the car loan ($15,000) instead, clearing it at month 40 — twenty months earlier, and a visible win in the middle of a five-year slog. The price of that win is $234 in extra interest and one extra month at the end.
$234 over five years is the honest answer for a portfolio shaped like this one, where the two mid-size debts sit two points apart on APR. It is not the answer for every portfolio — see below.
The behavioral tradeoff
The avalanche always wins on math. That's not a judgment call — it's arithmetic. Any dollar diverted from the highest APR is, by definition, earning a lower interest rebate. But the snowball wins on something the math doesn't see: momentum. Clearing an entire debt — closing a tab in your financial life — is qualitatively different from watching a single balance shrink. It produces a visible win, often within the first few months, and visible wins keep people in the chair.
If you've started and stopped a payoff plan before, that's a strong signal the behavioral payoff matters for you. The snowball costs a few hundred to a couple thousand dollars on a mid-size portfolio. If that's the difference between finishing in five years and quitting after six months, take the deal. If you know yourself well enough to grind through 63 months on autopay without quitting, take the math.
When the gap is bigger — or smaller
The cost of choosing snowball over avalanche scales with two things: the APR spread between your debts and the balance inversion (small balance happens to have low APR, large balance happens to have high APR). If all your debts are within a couple of APR points of each other, the two methods finish within a month and a few dollars of each other — pick whichever you will actually do. If you have a $500 store card at 28% and a $20,000 car loan at 4%, the snowball would burn money for years to clear the small one first; the avalanche is clearly correct.
Run your own numbers
Both methods are implemented as calculators on this site using the same input format, so you can swap between them and watch the totals change. Enter your real debts and your real extra payment, and the difference will either be loud enough to take seriously or small enough to ignore.
- Debt-Free Date calculator — both orders side by side, with the two payoff dates and the gap between them.
- Debt Avalanche calculator — highest-APR-first, minimum total interest.
- Debt Snowball calculator — smallest-balance-first, fastest first win.
- Debt Consolidation calculator — compare both against rolling everything into a single new loan.
Neither order does anything at all without an extra payment. If yours is currently $0, start with the minimum payment trap to see what standing still costs, then how to pay off debt fast for where the extra money comes from.