Debt Avalanche Calculator

Debt avalanche payoff calculator (highest interest first)

The debt avalanche method is a simple rule for paying off multiple debts while minimizing interest. You keep paying the minimum payment on every debt, and you direct any extra money to the debt with the highest APR. Once that debt is fully paid, you roll that payment into the next-highest APR debt, and repeat. Over time, your payment “snowball” grows, but the key difference is that avalanche prioritizes interest rate, not balance size.

This calculator estimates how your payoff could look if your balances and interest rates stay stable and you keep making the same monthly payments. You will see an estimated payoff timeline, an estimate of total interest paid, and a payoff order. If you choose the comparison option, the calculator also runs the same inputs through the debt snowball method (smallest balance first) so you can compare speed and interest cost side by side.

Use this as a planning tool, not a promise. Real statements may apply interest daily, add fees, change minimum payments, or change rates over time. Even with those differences, avalanche logic stays the same: protect minimum payments first, then attack the highest APR with everything else you can reliably add each month.

Assumptions and how to use this calculator

• Interest is estimated monthly using APR ÷ 12 and applied before each month’s payments.
• Minimum payments are treated as fixed amounts (your actual minimum may change as the balance changes).
• Extra monthly payment is applied after all minimum payments, and rolls to the next target if a debt is paid early.
• Fees, penalties, balance transfers, promotional rates, and new spending are not included.
• Results are estimates; if your payments are too low to reduce balances, the calculator will flag it as not payable.

Common questions

What is the debt avalanche method in plain terms?

You pay the minimum on everything so you stay current, then you put every extra rand or dollar toward the debt with the highest APR. The goal is to reduce the most expensive interest first. When the highest-APR debt is gone, you move to the next-highest APR.

Is debt avalanche always the cheapest option?

If all else is equal and you stick to the plan, avalanche typically produces the lowest interest cost because it targets the highest interest rate first. The main reason people pick snowball instead is motivation: clearing a small balance early can feel rewarding and keep you consistent. This calculator can compare both so you can decide which trade-off you prefer.

What if I do not know my exact minimum payment?

Use your typical minimum from recent statements. If you are unsure, it is better to slightly overestimate the minimum than underestimate it, because underestimating can make the plan look easier than it really is. If your minimums change a lot, treat the result as a rough range and rerun it when you have clearer numbers.

Why does the calculator say my debts may not be payable?

If your monthly payments are too low to cover interest across your debts, some balances can grow instead of shrink. This can happen when a minimum payment is extremely low relative to the APR, or when there is no extra payment available. The fix is straightforward: increase the extra payment, increase one or more minimum payments, reduce the APR (for example via refinancing), or remove new spending on revolving accounts.

How can I make the estimate more accurate?

Use current statement balances, the APR shown on each account, and the minimum payment shown on your statement. If you have a debt with a promotional rate that will change later, rerun the calculator with the future APR as a separate scenario. If your lender uses fees or daily compounding, the real result may differ, but the payoff order logic still holds.