Debt Payoff Calculator — Snowball vs Avalanche
Add each debt with its balance, interest rate, and minimum payment, then set an extra monthly amount. CalcWize simulates both the snowball (smallest balance first) and avalanche (highest rate first) methods month by month, showing how long until you’re debt-free, the total interest, and which strategy saves more.
Snowball vs avalanche
Both methods pay every minimum and throw a fixed extra at one debt at a time. Snowball targets the smallest balance first for fast, motivating wins; avalanche targets the highest interest rate first, which is mathematically the cheapest. The right one is the one you’ll actually stick to.
Why the extra payment is everything
Paying only minimums on high-rate debt can take years and cost a fortune in interest. The extra amount — funneled to one debt and then rolled onto the next as each clears — is what turns years into months. Even a small, consistent extra changes the picture dramatically.
When the maths and the motivation disagree
Avalanche usually saves the most interest, but the difference is often small when balances are similar. If quick wins keep you going, snowball’s slightly higher cost can be worth it — actually finishing beats optimising on paper.
Common mistakes
Taking on new debt while paying off the old; ignoring the interest rate and just attacking the biggest balance; and keeping no emergency buffer, so a surprise expense pushes you straight back onto the cards.
Frequently asked questions
- Which is better — snowball or avalanche?
- Avalanche costs less in interest because it kills the highest rate first. Snowball clears whole debts sooner, which many people find more motivating. When the interest difference is small, pick the one you’ll actually stick with.
- Should I pay off debt or save first?
- Build a small emergency buffer first so a surprise doesn’t send you back to borrowing, then attack high-interest debt aggressively. Saving at 4% while carrying 20% card debt loses money every month.
- Does consolidating help?
- A lower-rate consolidation loan can cut interest and simplify payments — but only if you don’t run the cleared cards back up. This tool models your existing debts, not a consolidation offer.
How we calculate it
CalcWize simulates month by month: interest accrues on each debt, every minimum is paid, then the extra — plus the freed-up minimums of any cleared debts — is funneled to one debt: the smallest balance for snowball, the highest rate for avalanche. It runs both strategies and compares the total interest.
What it doesn't do
- Debt consolidation or balance-transfer modelling
- Loans with changing rates or fees
- Tax or legal advice on debt — speak to a professional
Last reviewed: 2026-05