Add your debts, pick an extra monthly payment, and see exactly how many months each payoff strategy takes and how much interest it costs. Nothing leaves your browser.
How it works
Both strategies are run as a month-by-month simulation, not a formula: each month, interest accrues on every balance, minimum payments go out on all debts, and your extra payment (plus the minimums freed up by any debt you've already paid off) is thrown entirely at whichever debt is highest-priority for that strategy — highest APR first for avalanche, smallest balance first for snowball.
FAQ
Why does this simulate month-by-month instead of using a formula?
Because once a smaller debt is paid off, its minimum payment gets redirected onto the next target debt — that waterfall effect changes the payment amount every month, which has no simple closed-form formula to solve directly.
Which strategy actually saves more money, snowball or avalanche?
Avalanche (highest APR first) always pays the same or less total interest than snowball (smallest balance first), because it eliminates the most expensive debt fastest — snowball's advantage is psychological, giving faster visible wins to help you stay motivated.
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