If you have several debts and any money beyond the minimum payments, the order you attack them in changes both how fast you finish and how much interest you pay along the way. The two classic strategies are the snowball and the avalanche — and the baseline they both improve on is doing nothing extra at all.
Neither strategy requires more money than you are paying now plus whatever extra you can commit. The difference is purely about targeting.
The Baseline: Minimums Only
With no strategy, you pay each debt's minimum and nothing more. This is the slowest, most expensive path: high-rate balances linger for years, and most of what you send is interest. It is still worth modeling, because it is the honest benchmark — every strategy's "savings" is measured against it.
Snowball: Smallest Balance First
The snowball method lists your debts from smallest balance to largest, ignoring interest rates. You pay minimums on everything, and every extra dollar goes at the smallest debt until it is gone. Then you move to the next smallest.
The appeal is psychological. Killing off a small debt in the first month or two delivers a visible win: one fewer bill, one fewer creditor, real momentum. For many people, that motivational payoff is the difference between sticking with a plan and abandoning it — and an abandoned plan saves nothing.
Avalanche: Highest Rate First
The avalanche method lists debts from highest effective interest rate to lowest. Extra money attacks the most expensive debt first, regardless of its size.
This is the mathematically optimal order: every dollar aimed at the highest-rate balance stops more interest from accruing than a dollar aimed anywhere else. Over the full payoff, avalanche always costs the same or less than snowball and finishes at the same time or sooner. The catch is that if your highest-rate debt is also your largest, the first victory can be a long time coming.
Note the word effective rate: a card in a 0% promotional window or a loan on a special plan does not rank by its headline rate, which is why flagging those plans matters before choosing an order.
The Rollover: Why Both Methods Accelerate
Both strategies share the mechanic that gives the snowball its name. When a debt is paid off, you do not pocket its minimum payment — you roll it into the extra amount attacking the next target.
Say you pay $900 a month across all debts: $700 in minimums plus $200 extra. When the first debt (with a $75 minimum) is gone, the next target now receives $275 extra on top of its own minimum. Your total outlay never changes, but the firepower aimed at each successive debt keeps growing. This compounding rollover is why the last debts on the list often fall much faster than the first.
Which Should You Choose?
The honest answer: the one you will actually follow. The avalanche is cheaper on paper, but the gap between the two methods is often smaller than people expect — sometimes a few hundred dollars and a month or two over a multi-year payoff, though it can be much larger when rates vary widely across your debts.
That is why it is worth running your real numbers instead of guessing. The free Shouldirefi Analysis Tool projects both strategies (and the minimums-only baseline) for your actual debts, showing estimated payoff dates and total interest for each so you can see exactly what the motivational comfort of the snowball would cost you — often it is little enough to be an easy choice.
All figures are estimates for informational purposes only — not financial advice. Consult a qualified professional before making financial decisions.