Debt Payoff Calculator
Compare the snowball and avalanche methods side by side to see which clears your debt faster and for less interest.
Last updated
Debt Snowball
Debt Avalanche
How it works
Enter each debt's balance, interest rate, and minimum payment (you can leave Debt 2 and 3 blank if you only have one or two debts). Add any extra amount you can put toward debt each month, and the calculator runs a month-by-month simulation of both strategies at once. Each month, it applies interest to every remaining balance, then pays each debt's minimum, then takes whatever's left over, your extra payment plus the minimum payments freed up from any already-paid-off debts, and throws it entirely at one target debt. In debt snowball, that target is always the smallest remaining balance. In debt avalanche, it's always the highest interest rate. The simulation keeps running until every balance hits zero, tracking both the number of months and the total interest paid along the way.
For example, with three debts, $4,000 at 22% APR with a $100 minimum, $1,500 at 18% APR with a $50 minimum, and $8,000 at 7% APR with a $150 minimum, plus a $200 extra payment each month, snowball clears all three debts in 32 months and costs $2,025.60 in total interest. Avalanche clears them in 31 months and costs $1,957.23 in interest, about $68 less, because it prioritizes the 22% card ahead of the larger but cheaper 7% balance. Avalanche will always tie or beat snowball on total interest paid, but the two methods can be close, as they are here, when the highest-rate debt isn't dramatically larger than the smallest-balance one.
This simulation assumes fixed interest rates and fixed minimum payments for the life of each debt, and it assumes you commit the full extra payment amount every single month without adding new debt along the way. Real minimum payments on credit cards often shrink slightly as the balance goes down, and real APRs, especially on variable-rate cards, can change over time, so an actual payoff timeline may differ somewhat from this projection even if you follow the plan exactly.
Frequently asked questions
What's the difference between snowball and avalanche?
Debt snowball pays off the smallest balance first for quick psychological wins, regardless of that debt's interest rate. Debt avalanche pays off the highest interest rate first regardless of balance size, which mathematically minimizes the total interest you pay across all your debts.
What happens to a debt's minimum payment once it's paid off?
That freed-up minimum payment automatically rolls into the pool of money aimed at your current priority debt, on top of your extra payment, speeding up the rest of your payoff. This "snowballing" of freed-up payments is where the debt snowball method gets its name.
Which method actually saves more money?
Debt avalanche always saves the same amount of interest or more compared to snowball, since it always attacks the debt that's costing you the most per dollar first. In the calculator's own example scenario, avalanche saves about $68 and finishes a month sooner than snowball, though the gap can be much larger or smaller depending on how your specific balances and rates compare.
Why would anyone choose snowball if avalanche saves more money?
Because paying off a whole debt, even a small one, produces a real sense of progress that can help some people stay motivated and consistent with a payoff plan. Many people find that motivational boost worth a modest amount of extra interest, especially if the difference between the two methods is small for their specific debts.
Does the calculator account for minimum payments shrinking as a balance goes down?
No, it treats each debt's minimum payment as a fixed dollar amount for the entire simulation, even though many real credit card minimums are calculated as a percentage of the current balance and technically decrease as you pay it down. This is a simplifying assumption that keeps the comparison consistent between both strategies.
What if I only have one or two debts to pay off?
Just fill in Debt 1, and Debt 2 if needed, and leave any unused debt rows blank. The calculator only includes rows where you've entered a balance greater than zero, so empty rows are ignored automatically and won't affect the simulation.
Does this work for credit cards with variable interest rates?
You can enter a credit card's current APR and it will simulate as if that rate stays constant for the whole payoff period. Since variable-rate cards can have their APR change, particularly if a promotional rate expires or the prime rate shifts, treat the projection as an estimate based on today's rate rather than a fixed guarantee.
Working through a debt payoff plan? The Clever Fox Budget Planner is a well-reviewed monthly bill tracker built for staying on top of payments.
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