How debt snowball calculator works
The debt snowball method pays off debts in order from smallest balance to largest, regardless of interest rate. You pay the minimum on every debt and throw all your extra cash at the smallest-balance debt first. When that debt is gone, the minimum you were paying on it rolls forward onto the next-smallest debt, so the amount attacking each successive debt grows like a snowball.
This calculator simulates that process month by month. Each month it accrues interest on every outstanding debt, pays each minimum, then applies your extra payment (plus the freed minimums of any debts already cleared) to the current target debt. It reports the payoff order, the month each debt is cleared, a payoff date from a start date you choose, total interest paid, and total paid.
The snowball is popular because clearing small debts fast gives quick wins that keep you motivated, even though it may cost slightly more in interest than the avalanche method. Use the Strategy selector to compare: snowball targets the smallest balance first, avalanche the highest interest rate first (usually the least total interest). This is a planning estimate for fixed-rate debts with level minimums and does not model rate changes, fees, or varying minimums.