If you carry several debts, the order you attack them in matters — and the internet has argued for years about the two main strategies. The truth is that both work, they optimize for different things, and the best method is the one you'll follow to the end.
The two methods in one minute
Both start the same way: pay the minimum on everything, and commit every spare unit of money to one target debt. With the snowball, the target is the smallest balance; when it's gone, its whole payment rolls into the next smallest, and the 'snowball' grows with each payoff. With the avalanche, the target is the highest interest rate first — mathematically the cheapest possible path.
What the math says
The avalanche always wins on paper — it minimizes total interest by definition. But the margin depends on your debts. If your rates are close together (say a cluster of loans between 8% and 14%), the difference is often surprisingly small: a few percent of total interest. If one debt towers over the rest — a 29% store card among 6% loans — the avalanche's advantage becomes serious money.
What the behavior research says
Debt payoff is a years-long project, and abandonment is the real enemy — not a suboptimal ordering. Research on borrowers has repeatedly found that people who concentrate payments and score early wins are more likely to stay the course; each cleared debt is visible proof the plan works. That's the snowball's superpower: it front-loads motivation, and it also simplifies your life fastest by reducing the number of bills.
How to actually choose
Run your real numbers both ways in our debt snowball calculator — it shows the debt-free date and total interest for each method side by side. If the avalanche saves you a trivial amount, take the snowball's psychology for free. If it saves you a large sum, consider a hybrid: knock out one tiny debt first for the win, then switch to attacking the expensive one.
Whichever you choose, the real lever is the extra payment. Adding even a modest fixed amount above the minimums shortens the timeline far more than the choice of ordering does. Automate it, and let the rollover do the rest.
Mistakes that stall a payoff plan
The most common one is not accounting for new spending on the cards being paid down — every new charge undoes progress, and a plan built on shrinking balances can quietly stop working if a card is still in daily use.
Another is picking a method and never re-running the numbers as balances change; if a promotional rate expires or a balance transfer changes the picture, the 'right' target debt can change too.
Underestimating the minimum-payment trap is a third: minimums are set low on purpose by lenders, and a plan with zero extra payment can take a decade or more even on modest balances — the extra payment isn't optional if you actually want a payoff date within a few years.