Debt Avalanche Calculator
Free Debt Avalanche Calculator
The avalanche method targets your highest interest rate first because it's the mathematically optimal way to pay off debt. Enter your debts below, add whatever extra amount you can pay each month, and see your debt-free date, exactly how much interest you'll pay, and how that compares to the snowball method with your actual numbers. Everything runs right here in your browser: no signup required, and nothing is sent anywhere unless you choose to save your plan. Some example debt accounts have been added; edit, add or remove them as needed.
| Debt name | Balance | APR % | Min. payment |
|---|
Your balance over time
This plan Minimum payments only
Your payoff order
| # | Debt | Balance | APR | Paid off | Interest paid |
|---|
Month-by-month payment schedule
This is exactly where each dollar goes every month. Watch the payments roll: when a debt disappears, its column empties and the next debt's payment jumps.
Like what you see? Make it a real plan.
This calculator shows a snapshot. A free Undebt.it account keeps this plan updated every time you make a payment, tracks your progress, and shows your debt-free date getting closer every month.
Takes about a minute. No credit card needed. Your debts above carry over automatically — no re-typing.
How the debt avalanche calculator works
The debt avalanche method lines up your debts from highest interest rate to lowest. You pay the minimum on everything, and your extra payment attacks the highest-APR debt until it's gone. Then that entire payment — minimum plus extra — rolls onto the next-highest rate on the list. Because every extra dollar always targets the most expensive debt you have, the avalanche is the payoff order that minimizes total interest. No other ordering beats it mathematically.
This calculator runs that exact simulation month by month with your numbers: it accrues interest on each balance, applies your payments, retires debts in rate order, and rolls freed-up minimums forward until every balance hits zero. The comparison line under your results shows what the snowball (smallest balance first) would cost or save with the same debts — in real dollars and months, not internet arguments. Notice the sample data above: the smallest debt is a 0% medical bill. The snowball attacks it first; the avalanche correctly leaves it for last, because paying extra on an interest-free debt while a 26.99% card compounds is exactly the leak the avalanche plugs.
Prefer the motivation of quick wins? The debt snowball calculator runs the same engine ordered by smallest balance first or you can compare them side by side. For the full story on both methods, read how the debt snowball & avalanche methods work. Once you get signed up, there's plenty of help along the way if you need it. Check out how Undebt.it works for some more detailed information.