Debt Stacking Calculator

This calculator uses the avalanche method -- it always targets whichever debt currently carries the highest interest rate, not the smallest balance, and rolls each cleared debt's minimum payment into the next avalanche target. Avalanche minimizes total interest paid mathematically, though a smallest-balance-first "snowball" approach some people prefer for the psychological win of an early payoff isn't the ordering this calculator simulates.

Not measurably — Debt 1 APR shows zero effect on Total Months to Debt-Free at this calculator's defaults, because that output is a whole-number month count and a 10% rate nudge doesn't shift which month the last balance crosses zero. The same rate nudge does move Total Interest Paid by a few percent, just not the integer months figure.

Debt 2 Balance, moving Total Interest Paid by roughly 21% under a 10% nudge — the single largest driver of that output, ahead of Debt 3 Balance (about 16%) — a different input than the one that dominates Total Months to Debt-Free (Debt 3 Balance), since a bigger Debt 2 balance sits accruing interest at its own 14.5% rate for longer before the cascade reaches it.

Debt 1 Balance, moving First Debt Paid Off by roughly 25% under a 10% nudge — by far the largest effect of any input on that output. Debt 1 carries the highest rate at this calculator's defaults (24.9%), so it's always the first target of the avalanche ordering (line 76), and its own balance directly sets how many months that first payoff takes.