How the snowball and avalanche methods work
Both strategies share the same engine: you keep paying the minimum on every debt, then take whatever extra cash you have and pour it onto a single target debt. When that debt is gone, its old minimum plus your extra rolls onto the next target — the payment "snowballs" and gets bigger with each debt you clear. The only difference between the two methods is which debt you target first.
The avalanche method attacks the debt with the highest APR first. Because you're killing your most expensive interest first, this approach always pays the least total interest and is usually the fastest mathematically. The snowball method instead attacks the smallest balance first, regardless of rate. You may pay slightly more interest, but you clear whole debts quickly — and that early momentum is what keeps many people going.
This calculator simulates both methods month by month: it accrues interest on each balance, applies every minimum, then rolls your snowball pool onto the target debt in the right order until everything hits zero. Read the full walkthrough in our snowball vs avalanche guide, or see the exact assumptions on our methodology page.
Frequently asked questions
- What's the difference between the debt snowball and avalanche?
- Both pay minimums on everything and throw spare money at one target debt. The snowball targets the smallest balance first for quick wins; the avalanche targets the highest APR first to minimise interest.
- Which method saves the most money?
- The avalanche always pays the least total interest, because it eliminates your most expensive debt first. The snowball can cost a little more but clears individual debts faster, which is easier to stick with.
- Does this store my numbers?
- No. The whole simulation runs in your browser. Nothing you type is uploaded or saved on a server.