Debt Avalanche Calculator - Highest-Rate Payoff

The debt avalanche method ranks balances by interest rate and sends every extra dollar to the costliest debt while other accounts receive only their minimums. That order minimizes interest if you actually stick with it. The debt avalanche calculator estimates how many months a chosen monthly payment takes to clear one high-rate balance under compound interest, which is the first step in an avalanche plan and a useful bound when several cards are rolled into a single target payment. The closed-form payoff time for a fixed payment is n = −ln(1 − B × r / P) / ln(1 + r), then rounded up to a whole month. B is the balance, r is the annual rate divided by 1,200, and P is the payment. If P is not larger than B × r, interest equals or exceeds the payment and the balance never falls. A $10,000 balance at 22% with $500 a month takes 26 months. $5,000 at 18% with $300 takes 20 months. $20,000 at 25% with $1,000 takes 27 months. Avalanche is the interest-minimizing cousin of the debt snowball, which ranks by smallest balance instead. Avalanche usually costs less; snowball often feels faster because small accounts close sooner. Use avalanche when the rate gap is wide — a 25% card versus an 8% installment loan — and you can tolerate leaving a small cheap balance open. Use the estimate to size the payment you must send to the top-rate account after funding minimums elsewhere. This estimate treats one balance and one payment. A true multi-account avalanche rolls the freed minimum onto the next-highest rate after each payoff, which shortens later accounts. Fees, penalty APRs, variable rates, and skipped payments are not modeled. Credit-card minimums that shrink with the balance free cash over time; entering a fixed P is conservative if you will keep paying the same dollar amount. Recalculate when the rate, the target payment, or the balance changes, and compare the month count with a refinance or balance-transfer offer. If a transfer fee plus a lower rate beats 26 months of 22% interest, the avalanche number is the baseline you needed. The debt avalanche calculator will not prioritize accounts for you; sort by APR yourself, then use the months figure as the plan for the current top target.