Multi-Debt Payoff Planner: Snowball and Avalanche

This Multi-Debt Payoff Planner models snowball and avalanche with realistic monthly behavior. You add balances, APRs, and minimums; set a total monthly budget; and the tool allocates payments, rolls freed minimums to the next target, and tracks interest until you are debt-free. Choose snowball if motivation from quick wins helps you keep going. Choose avalanche if your goal is the least interest paid. Both strategies pay every account’s minimum first, then send the extra to a single priority debt, which changes as accounts close.

Inputs that improve accuracy: use your statement minimum payments and each account’s real APR. If your card lists a daily periodic rate, multiply by 365 for APR. Your budget is the total you can put toward these debts every month. The calculator automatically prevents negative amortization and caps the final payment so balances never go below zero. You can simulate windfalls using the one-time lump sum applied in month one to the current priority account.

• Snowball: smallest balance first, then next smallest once it closes.
• Avalanche: highest APR first for maximum interest reduction.
• Tie-breaker: when balances or APRs tie, the older row wins to keep results predictable.

The results show months to debt-free, total paid, and total interest. A compact snapshot highlights Month 1, Month 6, Month 12, Month 24, the midpoint, and the final month so you can scan progress on a phone without scrolling a long table. You can also download a CSV payoff schedule for spreadsheets. The compare view runs both methods on the same inputs so you can see the trade-off between speed and interest cost.

Treat the output as planning data, not promises. Real statements may include fees, compounding quirks, and timing rules. Re-run the plan if your balances, rates, or budget change. Most importantly, pick a payment you can stick to—consistency beats intensity.

Strategy tips: automate payments the day after payday, pause new purchases on the targeted cards, and direct windfalls to principal. If motivation is your bottleneck, start with snowball. If you are disciplined and want the lowest cost, pick avalanche. Either way, the Multi-Debt Payoff Planner keeps your plan organized and mobile-friendly so you can review it in seconds and stay on track.

Each month the tool computes interest for every open account using r = APR÷12. It pays each minimum, then allocates your remaining budget to one priority debt based on the selected rule. When an account closes, its minimum is rolled into the budget for the next month (the classic “debt snowball” effect). For a fixed budget and r > 0, months to payoff are simulated iteratively because minimums and allocations change as balances fall. CSV rows list payment, interest, principal, and end balance for every account and month.