Debt Payoff Calculator
List your debts and compare the snowball and avalanche payoff methods side by side. See your debt-free date, the order each debt clears, and how much interest each plan costs.
Debt-Free With the Avalanche Method
How It Works
Both payoff methods work the same way each month: you pay the minimum on every debt, then send all your extra money to one target debt. When a debt is paid off, its minimum payment rolls onto the next target, so your payments snowball bigger over time. The only difference is which debt you target. The formula each month is interest = balance × APR ÷ 12, then the balance falls by whatever you pay above that interest.
The avalanche targets the highest APR first, which always costs the least total interest. The snowball targets the smallest balance first, which clears whole debts sooner and keeps motivation high. The calculator simulates both plans month by month so you can compare the real numbers instead of guessing.
Worked example: three debts — a $5,000 credit card at 24% APR (minimum $125), a $1,200 store card at 19.99% APR (minimum $35), and an $8,000 personal loan at 10% APR (minimum $200) — with $200 extra a month. The avalanche clears the credit card in month 19, the store card in month 22, and the loan in month 35, costing $2,847.39 in interest. The snowball clears the store card in month 6, the credit card in month 24, and the loan in month 35, costing $3,027.22 — $179.83 more than the avalanche. Paying only the minimums with no extra would take 78 months and cost $7,329.01 in interest.
How to Use This Calculator
- List your debts. For up to four debts, enter a name, the balance, the APR and the minimum monthly payment. Leave the balance blank on Debt 4 to skip it.
- Enter your extra monthly payment. This is the money you can pay on top of all the minimums. It goes entirely to one target debt each month, chosen by your method.
- Compare the results. The calculator simulates both plans month by month and shows your debt-free date, the total interest each method costs, the payoff order for each plan, and a month-by-month schedule. You can download the avalanche schedule as a CSV file.
Both methods pay the minimum on every debt each month and send all extra money to one target. When a debt is paid off, its minimum payment rolls onto the next target, so your payments grow larger over time. The avalanche targets the highest APR first; the snowball targets the smallest balance first.
Tips and Practical Advice
The avalanche always costs the least total interest, because it removes the most expensive debt first. In the worked example above, the avalanche costs $2,847.39 in interest versus $3,027.22 for the snowball — a saving of $179.83. But the snowball clears the first debt in month 6 instead of month 19, and that early win keeps many people motivated. The best method is the one you will actually stick with, so if quick wins help you stay on track, the snowball's small extra cost may be worth it.
Whatever method you choose, the extra payment is what makes the plan work. In the same example, paying only the minimums with no extra would take 78 months and cost $7,329.01 in interest — more than double the interest of either plan. Even a modest extra amount shortens the payoff dramatically, because every extra dollar goes to principal and stops earning interest for the lender.
Two warnings before you start. First, every debt's payment must cover at least one month of interest, or the balance grows instead of shrinking — the calculator flags this instead of showing a misleading payoff date, so raise a minimum or the extra amount until every debt moves down. Second, the plan assumes fixed APRs, no new charges and no fees, so stop adding new charges to the cards you are paying off, or the numbers will not hold. These figures are estimates, not financial advice.
Frequently Asked Questions
What is the difference between the snowball and avalanche methods?
Both methods pay the minimum on every debt each month and send all extra money to one target debt. The snowball targets the smallest balance first, so you clear whole debts sooner. The avalanche targets the highest interest rate first, so it always costs the least total interest. When a debt is paid off, its minimum payment rolls onto the next target.
Which method saves more money?
The avalanche always saves the most money, because it removes the most expensive debt first. In the worked example on this page, the avalanche costs $2,847.39 in interest versus $3,027.22 for the snowball — a saving of $179.83. The snowball's advantage is motivation: it clears the first debt in month 6 instead of month 19.
How does the calculator handle minimum payments?
Every month, the minimum payment you entered is paid on each debt that still has a balance. Any extra amount you enter goes entirely to the target debt chosen by your method. When a debt reaches zero, its freed-up minimum payment is added to the extra amount and rolls onto the next debt.
What if my payment does not cover the interest?
If a debt's minimum payment is less than one month of interest on that debt, its balance grows instead of shrinking and the plan cannot finish. The calculator flags this instead of showing a misleading payoff date. Raise the minimum payment or the extra monthly amount until every debt's payment covers its interest.
Does this calculator include fees or new charges?
No. The calculator assumes fixed interest rates, no new charges, no late fees and no promotional rates that expire. Real card statements may differ slightly because most issuers charge interest on the average daily balance rather than the monthly balance.
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