Debt Avalanche vs. Snowball Calculator
Two ways to attack the same debt. The avalanche targets your highest interest rate first and costs the least. The snowball clears your smallest balance first for a faster early win. Enter your debts below and see both, side by side, in real dollars and months.
Your debts
How the comparison works
- Every month, simulated: interest accrues on each balance at APR ÷ 12, every minimum gets paid, then your extra payment — plus any minimums freed up from debts already cleared — goes to a single target debt.
- Avalanche target: the unpaid debt with the highest APR. Snowball target: the unpaid debt with the smallest balance.
- Freed minimums roll forward. When a debt hits zero, its old minimum joins the attack on the next target. This "snowballing" of payments is where most of the acceleration comes from.
- The honest tradeoff: avalanche wins on total interest, always. Snowball usually delivers the first zero balance sooner. If that early win is what keeps you paying, it can beat the mathematically perfect plan you quit.
Frequently asked questions
Which is better: the debt avalanche or the debt snowball?
Mathematically, the avalanche (highest interest rate first) always costs less in total interest. The snowball (smallest balance first) usually clears its first debt sooner, which many people find more motivating. Research on real debt accounts found that closing an account — any account — predicted eventually clearing all debt, so if quick wins keep you consistent, the snowball's slightly higher cost can be worth it.
How does this calculator decide the payoff order?
Each simulated month it applies interest, pays every minimum, then sends your extra payment (plus the minimums freed up from debts you've already cleared) to one target debt: the highest APR for avalanche, the smallest balance for snowball. It repeats until every balance is zero.
What if I can only afford minimum payments?
Then both strategies produce the same result — with no extra payment there is nothing to prioritize. The avalanche/snowball choice only matters once you pay more than the minimums.
What does the negative amortization warning mean?
It means a debt's minimum payment is smaller than one month of interest, so the balance grows even while you pay. That debt can never be cleared at the current payment — you need to pay more than the monthly interest charge.
Does the calculator assume I stop using the cards?
Yes. It assumes no new charges. New spending while paying down debt will change every number, usually for the worse.
How accurate is the monthly interest math?
Most US credit cards accrue interest daily, but monthly compounding at APR ÷ 12 is a very close approximation and matches how payoff timelines are conventionally quoted. Treat results as planning estimates, not bank statements.