Debt Payoff Calculator
List your debts below and add an extra monthly amount. The calculator simulates both payoff strategies side by side — payoff order, total interest, months to debt-free, and your debt-free date.
❄️ Snowball (smallest balance first)
🏔️ Avalanche (highest APR first)
What the results mean
- Debt-free in — months until the last balance hits zero under each strategy.
- Total interest — everything you will pay beyond the borrowed amounts. Avalanche always wins here (or ties).
- Payoff order — the sequence debts disappear. Snowball clears small balances first for quick wins; avalanche kills expensive rates first.
The green-highlighted panel shows which method saves more interest on your numbers. If snowball wins your motivation and avalanche wins your wallet, pick the one you will actually finish.
How it works
- Debts are ordered by strategy: smallest balance first (snowball) or highest APR first (avalanche).
- Each month, interest accrues on every remaining balance, then minimums are paid on all debts.
- Everything left from your monthly budget (minimums + extra) attacks the current target debt.
- When a debt is cleared, its minimum payment rolls into the attack on the next target — the "snowball" effect.
- The simulation repeats until all balances are zero, tracking total interest and the payoff order.
Formula
There is no single closed-form formula for payoff order — it is a month-by-month simulation. The key mechanic: payment budget = sum of all minimums + extra, with freed minimums compounding onto the next target.
Example
Example: $5,000 card at 20% (min $100) + $2,000 loan at 10% (min $50), $200/month extra
- Snowball clears the $2,000 loan first, then the card — debt-free in about 25 months.
- Avalanche attacks the 20% card first — debt-free in about 24 months, saving roughly $267 in interest.
- Either way, that $200 extra is doing the heavy lifting: without it, the same debts take about 82 months — over three times as long.
Use cases
- Choosing a strategy — see the real dollar difference between snowball and avalanche for your debts.
- Sizing extra payments — find the monthly extra that gets you debt-free by a target date.
- Windfall decisions — model where a tax refund or bonus shortens the timeline most.
- Staying motivated — the payoff order gives you concrete milestones to celebrate.
Frequently asked questions
What is the debt snowball method?
Pay minimums on everything, then throw all extra cash at the smallest balance first. When it is gone, roll its payment into the next-smallest. The quick wins keep motivation high, even though it is not mathematically optimal.
What is the debt avalanche method?
Same structure, but you attack the highest interest rate first instead of the smallest balance. It always minimizes total interest paid — the math-optimal choice if you can stick with it.
Which method is better?
Avalanche saves more money; snowball wins on psychology. Studies on debt payoff consistently find that people who see early progress (snowball) are more likely to finish. Pick the one you will actually follow.
What counts as the 'minimum payment'?
The smallest amount your lender accepts each month without penalties. In the simulation, minimums are paid on every debt each month; your extra amount plus freed-up minimums all attack the current target debt.
What if a minimum payment doesn't cover the interest?
Then the balance grows despite payments — negative amortization. The calculator flags that plan as "never" and shows a warning. In real life, that is the signal to call the lender or a nonprofit credit counselor immediately.
Does the snowball vs. avalanche comparison work outside the US?
Yes. Minimum payments, monthly interest, and the payoff-order logic work the same in any country. Enter your balances in your own currency — APR works the same way in the UK, Canada, and Australia.
Related tools
Last updated: 2026-10-04 · WebTools Hub