Debt Payoff Calculator
List your debts, set an extra monthly payment, and see snowball vs avalanche side by side — your debt-free date and total interest for each.
Snowball vs avalanche
| Strategy | Debt-free in | Total interest |
|---|---|---|
| Snowball (smallest balance first) | ||
| Avalanche (highest rate first) |
How to use the debt payoff calculator
- Add each debt with its current balance, APR, and minimum monthly payment.
- Enter any extra amount you can pay each month on top of minimums.
- Click Compare strategies to simulate both payoff orders month by month.
- Pick the strategy that fits you — avalanche saves the most, snowball wins fastest psychologically.
Snowball vs avalanche, settled with math
There are two famous ways to attack multiple debts. The avalanche method targets the highest interest rate first, which mathematically minimizes total interest — every dollar kills the most expensive debt. The snowball method targets the smallest balance first, wiping out entire debts quickly for psychological wins that keep you motivated. Studies consistently show that motivation, not math, is why most payoff plans fail — which is why snowball devotees often finish even though avalanche is cheaper on paper. The difference is usually smaller than people expect: a few hundred dollars on typical balances, not thousands. This calculator simulates both strategies month by month — minimums everywhere, extra payment aimed at the current target — so you can see your actual debt-free date and total interest for each, then choose with eyes open. One caveat: the simulation assumes fixed rates and minimums and no new borrowing; real life is messier, but the comparison is honest.
Frequently asked questions
Which strategy should I choose?
Avalanche (highest APR first) always costs less in interest. Snowball (smallest balance first) clears individual debts faster, which helps motivation. The calculator shows both — pick the one you will actually stick with.
How is the interest calculated?
Monthly: each balance accrues balance × APR ÷ 12 each month. Minimums are paid on all debts, then your extra payment attacks the current target debt.
What if I can't afford extra payments?
Set the extra payment to $0. You will see the minimums-only timeline — often eye-opening, and a strong argument for finding even $50 extra a month.
How accurate is this?
It is a planning estimate: it assumes fixed APRs, fixed minimums, and no new charges. Real statements vary slightly, but the strategy comparison holds.