About this calculator
Two strategies dominate debt payoff plans. The snowball method pays the smallest balance first regardless of rate, building momentum through quick wins. The avalanche method pays the highest interest rate first, which is mathematically optimal. This calculator runs both side-by-side for up to three debts so you can compare total interest paid and time to debt-free.
How the calculation works
Each month, you pay the minimum on every debt and apply any leftover budget to a single "target" debt. The target is the smallest balance (snowball) or highest APR (avalanche). When the target is paid off, its minimum payment "rolls" into the next target — that's where the snowball metaphor comes from, and why both methods accelerate over time.
When to choose snowball vs avalanche
- Snowball wins when motivation matters more than math — the early payoffs create visible progress and reduce account count. Studies suggest snowball users finish at higher rates than avalanche users.
- Avalanche wins when the rate spread is wide (e.g., 22% credit cards mixed with 5% auto loans). The interest savings can be substantial — sometimes thousands of dollars over a multi-year plan.
- Hybrid works too: pay off one or two smallest debts for quick wins, then switch to avalanche for the long tail.
Before you start either strategy
High-APR credit-card debt (18%+) often deserves a balance transfer to a 0% intro APR card before any payoff plan — you can save thousands by parking the balance interest-free for 12–18 months. And always cover the minimums; missed payments destroy the credit score that lets you escape high-rate debt in the first place.