How the comparison works
Both methods start the same way: pay the minimum on every debt, then put every extra dollar on one target debt. When the target is paid off, its payment rolls into the next target, so your total monthly payment stays the same while more of it goes to principal.
- Snowball targets the smallest balance first.
- Avalanche targets the highest interest rate (APR) first.
Each month, the calculator adds interest at APR ÷ 12, pays the minimums, then applies the extra money and any freed-up minimums to the current target. It repeats until every balance reaches zero and reports the month each debt is paid off, the debt-free month and the total interest.
Reading the results
Avalanche usually costs less interest, because the most expensive debt shrinks first. Snowball clears whole accounts sooner, which many people find motivating. When the two results are close, pick the one you'll stick with. When avalanche saves a lot, that's a real reason to choose it.
If a debt's minimum payment is smaller than the interest it charges each month, that balance can never be paid off by minimums alone. The calculator flags this so you can add an extra payment.
Limits of a single scenario
The calculator assumes the same payment every month, fixed rates and no new charges. Real life is messier: promotional rates end, income changes, and some months have room for more. If your income is irregular, our snowball vs avalanche guide explains how to budget on a lean month and decide what to do with good months.
Frequently asked questions
Is the interest calculation exact?
It's an estimate. Lenders calculate interest daily or on an average daily balance and may charge fees, so your statements will differ slightly. The comparison between methods is what matters.
What should I enter as the minimum payment?
The minimum on your latest statement. Minimums on credit cards often fall as the balance falls; the calculator keeps them fixed, which pays debt off a little faster than paying only the shrinking minimum.
Are my numbers sent anywhere?
No. The math runs on this page in your browser. Nothing is saved, sent or logged.
Read the full guide
Sources
Results are estimates for planning, not professional advice. Check the official sources above for rules that apply to you.