Two ways to escape multiple debts. The math says one wins. Psychology says the other.
If you have more than one debt — a couple of credit cards, a car loan, maybe a student loan still hanging around — you have a problem most personal finance articles gloss over. You can't just "pay them off." You have to choose which one to attack first.
That choice matters more than people realize. The same monthly budget, applied to the same set of debts, can take 22 months or 30 months to clear depending on which debt you target first. The interest you pay can vary by thousands of dollars.
There are two main schools of thought. They've been argued about on personal finance forums for two decades. Both are valid. They optimize for different things.
The Avalanche method
Avalanche is the mathematically correct answer. You list your debts by interest rate, highest to lowest. You pay the minimum on everything, and you throw every extra dollar at the highest-rate debt until it's gone. Then you move to the next-highest. And so on.
This minimizes total interest paid. By definition. There is no other strategy that pays less interest, because you're always killing off the most expensive debt first. Every dollar of extra payment is doing maximum damage to the bank's profits.
If you're a spreadsheet person — if numbers genuinely motivate you — avalanche is the answer. The downside is that the high-rate debt is often a big debt, so you may not see a debt fully disappear for many months. That's psychologically tough.
The Snowball method
Snowball, popularized by Dave Ramsey, ignores interest rates entirely. You list your debts by balance, smallest to largest. You pay the minimum on everything, and you throw every extra dollar at the smallest debt until it's gone. Then the next-smallest. And so on.
Mathematically, this is suboptimal. You'll pay slightly more interest than avalanche, sometimes a lot more. But you get a quick first win. Knocking out a $500 credit card in two months feels real. It builds momentum. The "snowball" gets bigger and faster as each debt falls.
A 2016 study from Northwestern's Kellogg School of Management actually found that people who use snowball are more likely to finish their debt payoff. Not because the math is better — because they don't quit halfway through. The math you don't follow is worse than the math you do.
So which one wins?
The honest answer: it depends on you.
Run the numbers in the calculator above with your actual debts. Look at the difference. If avalanche saves you $200 over 22 months, the math advantage is real but not life-changing — pick whichever feels right. If avalanche saves you $5,000 over three years, that's a different conversation. Real money.
The other thing to look at is your debt distribution. If your highest-APR debt is also your biggest debt, avalanche makes you slog for a long time before the first win. If your smallest debt is also high-APR, avalanche and snowball will pick the same starting target — no contest.
What both strategies have in common
The thing that actually matters most isn't which debt you target first. It's the size of the "extra payment" — the dollar amount above your minimums that you're willing to commit each month. Doubling your extra payment from $100 to $200 cuts your payoff time by far more than choosing the optimal strategy.
The math will tell you which order to attack. But the budget tells you whether you'll attack at all.
About the calculation
Both strategies use month-by-month amortization. Each debt accrues interest at its own APR (divided by 12). The minimum payment is applied to each debt. The extra payment is applied entirely to a single "target" debt — the smallest balance for snowball, the highest APR for avalanche. When a debt is paid off, its minimum + share of extra is rolled over to the next target. The simulation runs until all debts are zero. We don't model new charges, fees, or rate changes. The methodology matches the consumer guidance published by the CFPB and used by major personal finance educators.