StrategyDebt is a free debt payoff calculator. You enter your debts — balance, interest rate, and minimum payment — plus any extra amount you can pay each month, and it shows a side-by-side comparison of the two most popular payoff strategies: how many months each takes, how much interest each costs, and the order your debts get cleared. Everything runs in your browser; your numbers never leave your device.
Both strategies pay the minimum on every debt and direct all remaining budget at one target debt. When a debt is paid off, its payment rolls into the next target, so your total monthly payment stays constant. Avalanche targets the highest interest rate first and is mathematically optimal — it always minimizes total interest. Snowball targets the smallest balance first; it costs somewhat more in interest but delivers fast early wins, which research shows helps people stick with a plan. The simulation accrues interest monthly (APR ÷ 12) on your exact numbers, so the difference you see is the real price of choosing motivation over math — often smaller than people expect.
This calculator is educational only. It is not a substitute for professional financial advice. Real loans can have fees, variable rates, promotional periods, and prepayment rules the model doesn't capture. For decisions about your specific situation, consult a qualified financial professional.
Updated July 2026