The engine both methods share
List your debts, pay every minimum, and commit a fixed extra budget — say $300 — to exactly one "target" debt. When any debt dies, its minimum payment doesn't go back into your lifestyle; it rolls onto the next target. The rollover is why either method beats paying "a bit extra on everything": concentration finishes debts, and finished debts feed the attack.
A worked example where the methods truly differ
Three debts: a $1,800 medical bill at 0%, a $6,500 credit card at 22.99%, and an $11,000 car loan at 7.5% — minimums $485 total, extra budget $300.
| Method | First target | Debt-free in | Total interest |
|---|---|---|---|
| Snowball | Medical bill (smallest) | 2 yr 5 mo | $2,803 |
| Avalanche | Credit card (22.99%) | 2 yr 4 mo | $2,321 |
Avalanche saves $482 here because every month the credit card survives, it bleeds ~23% annualized. But snowball delivers its first paid-off debt in month 6 — a win you can feel — while avalanche makes you grind at the biggest, ugliest rate first. Both finish within 1 month(s) of each other; the order and the interest differ.
Why avalanche always costs less (and why that's not the whole story)
Interest accrues fastest on the highest rate, so retiring high-rate dollars first minimizes total interest — that's a theorem, not an opinion, and our calculator's comparison will never show snowball winning on interest. But debt payoff is a years-long behavior problem, and research on real borrowers (including work popularized from the Kellogg School studies) finds people who experience early wins are more likely to finish at all. A plan that costs $482 more and gets completed beats a perfect plan that gets abandoned in March.
How to choose in 30 seconds
- Enter your debts in the calculator — it shows both methods side by side.
- Look at the interest gap. Under a few hundred dollars? Take snowball's motivation for free.
- Gap in the thousands (usually: big high-APR card + small low-rate debts)? Take avalanche — or a hybrid: knock out one tiny debt first for the win, then switch to avalanche order.
Two accelerators that beat both methods
- Rate reduction: a 0% balance-transfer card (mind the 3–5% fee) or a consolidation loan lowers the interest side directly; then run snowball/avalanche on what remains.
- Budget increases: the extra budget is the single most powerful variable — in the example above, $100 more per month cuts months off either plan. Even temporary boosts (tax refund, bonus) compound through the rollover. Track any loan's payoff with the loan payoff calculator.