Free Tool
Debt Payoff Calculator (Snowball vs Avalanche)
Enter up to 6 debts and an extra monthly payment to see how the snowball method (smallest balance first) compares to the avalanche method (highest rate first) — months to debt-free and total interest, side by side.
Snowball (smallest balance first)
Avalanche (highest rate first)
Assumptions: interest accrues monthly on the remaining balance (annual rate ÷ 12). Each month, every debt's minimum payment is made first; the extra payment then goes entirely toward one target debt — the smallest balance for snowball, the highest interest rate for avalanche. When a debt is paid off, its minimum payment amount rolls into the extra-payment pool for the rest. Both methods use the same total monthly payment, so any interest difference comes purely from the order debts are targeted.
Debt snowball vs. avalanche: which one pays off debt faster?
Both the snowball and avalanche methods do the same basic thing: pay the minimum on every debt, then throw every extra dollar at one target debt until it's gone, then roll that payment into the next target. The methods only differ in which debt they target first.
The snowball method targets your smallest balance first, regardless of interest rate. The appeal is psychological: you clear a whole debt off your list quickly, which builds momentum and makes the plan feel achievable — research on behavior change consistently finds this matters for people actually sticking with a payoff plan.
The avalanche method targets your highest interest rate first, regardless of balance. Mathematically, this is always the cheapest approach — it minimizes the total interest you pay over the life of the payoff plan, because it stops your most expensive debt from accruing interest the soonest.
In practice, the gap between the two methods depends entirely on your specific debts. If your smallest balance also happens to carry your highest rate, the two methods are identical. If your smallest balance has a low rate and a large balance is racking up interest at 24%, avalanche can save you meaningfully more — the calculator above runs both simulations on your actual numbers so you're not guessing.
One thing both methods share: the extra payment amount matters more than which method you pick. A bigger extra payment shortens your payoff timeline and cuts total interest far more than switching between snowball and avalanche does. If you're deciding between "which method" and "where do I find an extra $50/month," the second question usually matters more.
Whichever you choose, this calculator assumes you keep paying the same total amount every month and don't take on new debt in the meantime — real life is messier, so treat the output as a planning estimate, not a guarantee, and re-run it whenever a balance or rate changes.
Frequently asked questions
Which is better, debt snowball or debt avalanche?
Avalanche always results in equal or less total interest paid, because it targets your highest interest rate first. Snowball can be better for you personally if paying off a small balance quickly keeps you motivated to stick with the plan — the 'best' method is the one you'll actually follow through on.
What counts as 'extra payment' in this calculator?
Any amount above the combined minimum payments across all your debts that you can consistently put toward debt each month. The calculator applies 100% of that extra amount to one target debt at a time, then rolls a paid-off debt's minimum into the extra pool.
Why do the two methods sometimes give the same result?
If your smallest-balance debt also happens to carry your highest interest rate, both methods target the same debt first, so the results converge. The bigger your debts diverge on balance vs. rate, the more the two methods differ.
Does this calculator account for changing interest rates or new debt?
No — it assumes fixed interest rates and a fixed monthly payment for the whole simulation, with no new debt added along the way. Real-world variable rates, balance transfers, or new purchases will change your actual results, so re-run the numbers whenever something changes.
Want the full system, not just this one number?
This calculator runs one comparison. The Personal Budget & Debt Payoff Planner is a spreadsheet system that tracks up to 10 debts month by month, logs every payment against both methods, and pairs it with a full monthly budget tracker — so you can actually follow the plan, not just see the projection.
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