Method
Debt Avalanche vs. Debt Snowball
Two methods for prioritising payments across multiple cards. One wins on math. The other wins on motivation. Both beat the unstructured default by a wide margin.
Avalanche
Highest APR first
Pay the minimum on every card. Direct every extra dollar at the card with the highest APR. When that card is cleared, roll its full payment to the next-highest-APR card.
Snowball
Smallest balance first
Pay the minimum on every card. Direct every extra dollar at the card with the smallest balance. When that card is cleared, roll its full payment to the next-smallest balance.
Worked example
Two cards, $250 monthly budget
Pay min on Card B (~$30/mo), throw the remaining $220 at Card A. Card A clears first. Roll the full payment to Card B.
Pay min on Card A (~$60/mo), throw the remaining $190 at Card B. Card B clears first (fast win). Roll the full payment to Card A.
On this two-card example, avalanche saves roughly $60. The snowball clears Card B about eight months sooner, which some borrowers value more than the $60 of interest.
When snowball wins
A plan you stick to beats one you abandon
The snowball loses on math by 5% to 15% in total interest in most multi-card scenarios. It wins on adherence: the visible elimination of an entire account in the first few months tends to keep borrowers on the plan. Behavioural research from the Boston Consulting Group and the Journal of Consumer Research has consistently found that completion rates favour snowball-style methods, and a slightly suboptimal plan completed beats an optimal plan abandoned.
If past payoff attempts have stalled, snowball.
When avalanche wins
When the APR gap is wide
With one card at 28% (a penalty rate or store card) and another at 16%, the avalanche advantage grows. Every extra dollar on the 28% card saves more interest than the same dollar on the 16% card by a meaningful margin. In wide-gap cases, avalanche can save 15% to 25% over snowball.
With one card, both methods collapse into the same advice: pay as much as you can each month. Strategy choice only matters when there are multiple balances.
Often the actual winner
The 0% balance transfer beats both
On the same two-card $4,500 setup, transferring the full balance to a single 0% intro card with a 3% fee costs $135 in fees and clears the balance at zero interest, provided you can pay roughly $250/mo for the intro period. That beats both avalanche and snowball.