Ask around and you'll get two different answers to the same question: what order should you pay off debt in? One camp says smallest balance first, for the win. The other says highest interest rate first, for the math. Both are describing something real. They just disagree about what actually gets someone out of debt.
The debt snowball sorts by balance, smallest to largest, and throws every extra dollar at the smallest one until it's gone. The debt avalanche sorts by interest rate instead, highest to lowest, on the theory that whatever's compounding the fastest should get paid down first.
Neither is wrong. They're optimizing for two different things, and the honest answer to "which one should I use" depends on which of those two things matters more to you.
What each method optimizes for
Avalanche optimizes for total cost. Interest is compounding fastest on the highest-rate debt, so paying it down first stops the most expensive growth first. Run the math on nearly any real set of debts and avalanche comes out ahead in total interest paid, sometimes by a little, sometimes by a lot depending on how spread out the rates are.
Snowball optimizes for something math doesn't measure directly: whether the person doing the paying keeps doing it. Clearing an entire debt off the list, even a small one, is a different kind of progress than watching a total balance get smaller. It's visible, it's final, and for a lot of people it's the difference between staying motivated through month eighteen and quietly stopping around month six.
Snowball vs. avalanche, side by side
| Snowball | Avalanche | |
|---|---|---|
| Sorts debts by | Balance, smallest first | Rate, highest first |
| Optimizes for | Early wins, momentum | Total interest paid |
| First debt usually clears | Sooner | Later |
| Total cost over time | Usually more | Usually less |
| Works best if | You need to see progress to keep going | You trust the math and can wait for the win |
A middle option most comparisons skip
The choice isn't strictly one or the other. A common middle ground: if one debt is both small and low-priority under a strict avalanche order, some people clear it first anyway, purely for the early win, then switch to a strict highest-rate-first order for everything left. It costs a little in total interest and buys back some of the momentum snowball is built around. Whether that trade is worth it depends on how much that first win is actually worth to you.
How to actually decide
Sort your real debts both ways, even roughly. Note two things: how many months until the first debt clears under each order, and roughly how much total interest each order costs over the life of all your debts. If those two numbers are close, the decision mostly comes down to which kind of progress you trust yourself to stay motivated by. If they're far apart, that gap is worth knowing before picking either one.
For the mechanics of actually building either tracker by hand, the debt snowball walkthrough and debt avalanche walkthrough both go through it step by step.
Which matters more to you right now, paying less overall, or seeing a debt disappear sooner?