Debt Payoff Calculator (Snowball vs Avalanche)
Enter up to four debts and an extra monthly amount: both famous strategies are simulated on your real numbers — the order each attacks your debts, the months, and the interest each costs.
Two famous orders, one honest simulation
Avalanche: attack the highest APR first — mathematically optimal, never beaten on interest. Snowball: attack the smallest balance first — slightly costlier, but it manufactures early victories. This page does not argue; it simulates both on your actual debts and prints the orders, the months and the interest bills for you to judge.
Each month: minimums on everything, then all spare cash lands on the strategy's target debt
Example: debts of $500 at 12%, $2,000 at 25% and $5,000 at 7%. Snowball orders them $500 → $2,000 → $5,000 (balance order); avalanche orders them $2,000 → $500 → $5,000 (APR order). The default debts in the form are exactly these — run it and see the interest difference your balances produce.
The interest gap is usually smaller than the internet says
For typical consumer balances, the two strategies often differ by a few hundred dollars across years — real money, but not the chasm forum debates imply. The deciding variable is adherence: the strategy you are still executing in month nine beats the optimal one you abandoned in month three. The numbers above let you price your own psychology.
How this is calculated
Monthly simulation per strategy: interest accrues on each balance at APR ÷ 12; every minimum is paid; the extra amount, plus minimums freed by debts already cleared, cascades to the strategy's current target. Snowball sorts by balance ascending, avalanche by APR descending; the sort is re-checked as balances move. Figures are exact for the model (monthly interest — card issuers' daily model can differ slightly, as the card pages disclose).
Frequently asked questions
Which strategy is actually better?
On cost, avalanche — always, by construction. On completion, the evidence favors whichever produces early wins for the person paying. This page's honest service is showing you the price of snowball on your debts: if it is $80, take the motivation and run.
Should I include my mortgage or car loan?
You can — the simulation accepts any debts with a balance, APR and minimum. Most people run cards and personal loans here because their APRs dominate; including a mortgage stretches the timeline and dilutes the picture.
What if a minimum doesn't cover a debt's interest?
That debt grows even while 'paid' — the simulation will not clear it and the run will show the failure rather than hide it. That situation needs a different conversation (creditor hardship programs, consolidation, advice) before strategy selection.
Does the order ever change mid-plan?
Yes: when a debt dies, its minimum joins the attack on the next target — the cascade is the engine of both strategies, and equal balances/rates are broken in entry order.
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