Debt Avalanche Calculator
Pay off multiple debts for the least interest. Add each debt's balance, APR, and minimum payment, then set an extra monthly amount. The avalanche method attacks the highest-rate debt first and rolls each cleared payment forward — your payoff order, debt-free date, and interest saved update as you type.
The avalanche method pays every minimum, then throws all spare cash — your extra plus the minimums freed up by debts already cleared — at the highest-APR debt first, rolling forward as each one clears. Targeting the most expensive interest first clears the whole pile for the lowest total interest. Example: a card at 26.99% is attacked before a 7.5% car loan, even if the loan balance is larger.
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Add at least one debt with a balance to start.
Payoff order (highest APR first)
| # | Debt | APR | Balance | Min/mo | Cleared |
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Show month-by-month schedule
How to use the debt avalanche calculator
Add a row for each debt you owe. For every one, enter the balance still owed, its APR (the annual interest rate on your statement), and the minimum monthly payment. The name is optional and just helps you keep track. Use + Add debt for more rows, or the × button to remove one. Then set the extra payment per month — the amount you can pay on top of all your minimums.
The results update instantly. The big number is how long until you're debt-free; below it you'll see which debt to pay first, your debt-free date, the total interest you'll pay, and — crucially — the interest and time the avalanche saves you compared with paying only the minimums. Expand the payoff-order table to see the exact order and when each debt clears, or the month-by-month schedule to follow every balance down to zero.
Everything runs in your browser — the figures you type are never uploaded. This is a simplified estimate that assumes fixed rates and no new charges or fees; it is not financial advice.
How the avalanche method works
Each month, three things happen in order. First, interest is added to every debt at its monthly rate (the APR divided by 12). Second, the minimum payment is made on every debt. Third — and this is the heart of the method — all your remaining cash is thrown at a single debt: the one with the highest APR. That spare cash is your extra payment plus the minimums freed up by any debts you've already cleared, so the amount attacking your top-rate debt grows over time. This is the "avalanche": payments pile up and roll downhill onto the next debt as each one is wiped out.
Because you always pay down the most expensive interest first, the avalanche is the mathematically optimal order — it clears your total debt for the least interest possible given a fixed extra payment. The trade-off is patience: if your highest-rate debt also has a large balance, you may not clear any single debt for a while. The debt payoff calculator is handy for stress-testing one balance at a time, and the snowball method (smallest balance first) is the popular alternative when an early win matters more than saving every dollar of interest.
Avalanche vs snowball. The snowball orders debts by smallest balance, clearing whole accounts quickly for motivation. The avalanche orders by highest APR, minimising interest. For most people the two finish within a few months of each other, but the avalanche almost always pays less interest. The right choice is the one you'll actually stick with — and you can switch order in this tool simply by reading the highest-APR debt off the payoff-order table.
Common debt avalanche questions
What is the debt avalanche method? You pay every debt's minimum, then put all spare cash toward the highest-APR debt until it's gone, rolling each freed-up payment onto the next-highest-rate debt. Attacking the priciest interest first clears everything for the least total interest.
Avalanche or snowball — which should I use? The avalanche (highest APR first) saves the most interest. The snowball (smallest balance first) clears individual debts faster for a motivational boost but usually costs a bit more. This tool uses the avalanche order; pick whichever keeps you paying.
Does the avalanche or snowball save more money? The avalanche almost always saves more — paying the highest APR first minimises total interest, making it the mathematically optimal order. The snowball costs a little more but feels faster. The avalanche only meaningfully wins when there's a wide spread between your highest and lowest rates.
How much will the avalanche save me? The calculator compares your plan to paying only the minimums and shows the interest and time saved. The wider the spread between your highest and lowest APRs, and the more extra you pay, the bigger the saving.
Why does it warn that a debt will "never" be paid off? If a debt's minimum is smaller than its monthly interest, the minimum alone never reduces the balance. With the avalanche it's still cleared once your extra and freed-up minimums reach it — but adding more each month closes the gap far sooner.
Is my data private? Yes. The whole calculation runs in your browser; the balances, rates, and payments you enter are never uploaded or stored anywhere.