Debt payoff calculatorDebt payoff calculator: compare snowball and avalanche
Compare paying the smallest balance first (snowball) with paying the highest interest rate first (avalanche). Both simulations keep the same monthly budget: your original minimum payments plus the extra amount you enter. As a debt is cleared, unused money is applied to the next target. Compare total interest, payoff order, and estimated months; the result depends on your balances, rates, and budget rather than a universal savings claim.
Snowball
Debt-free in
2 yrs 5 mos
$3,062 total interest
- 1. Medical bill
- 2. Credit card
- 3. Car loan
Avalanche
Debt-free in
2 yrs 5 mos
$2,749 total interest
- 1. Credit card
- 2. Medical bill
- 3. Car loan
Avalanche saves $313 in interest on these debts. Snowball’s advantage is psychological: the first win arrives faster.
How to use
- 1
Add each debt with its balance, APR, and minimum payment.
- 2
Enter how much extra you can pay per month in total.
- 3
Compare the snowball (smallest balance first) and avalanche (highest APR first) strategies side by side.
- 4
Note the interest difference — then pick the strategy you will actually stick with.
- 5
Re-run as balances change; freed minimums roll into the attack automatically.
Benefits
Both strategies, one screen
See months-to-freedom and total interest for snowball vs. avalanche without doing either by hand.
Psychology meets math
The comparison shows what quick wins cost versus the optimal path — then you choose.
Handles real messiness
Multiple cards, loans, and rates simulated month by month, minimums and all.
A finish date to aim at
"Debt-free in 23 months" beats "someday" for staying motivated.
Snowball vs. Avalanche — when to pick each
Both strategies use the same extra payment budget and roll freed minimums forward. The only difference is which debt gets attacked first.
| Factor | Snowball | Avalanche |
|---|---|---|
| Attack order | Smallest balance first | Highest interest rate first |
| Total interest paid | Usually more | Always less or equal |
| Time to first payoff | Faster — first win sooner | Slower if smallest ≠ highest rate |
| Best for | Motivation — quick wins keep you going | Math — minimising total interest cost |
| When rates are similar | Both produce nearly identical results — pick whichever motivates you | |
The real winner? Whichever method you stick with. Research on behaviour consistently shows that people who pick snowball are more likely to keep going — the dopamine hit of clearing a debt matters. If you can stay disciplined with either, choose avalanche for the savings.
The cascade effect — why extra payments compound
When a debt is paid off, its minimum payment doesn't disappear — it joins your extra payment pool and attacks the next target. This cascade grows your firepower over time.
| Month | Event | Monthly attack pool |
|---|---|---|
| Start | 3 debts active, $300 extra | $300 extra only |
| Debt 1 cleared | $50 minimum freed | $350 → next target |
| Debt 2 cleared | $170 minimum freed | $520 → final target |
| Debt 3 cleared | All done | Redirect $800/mo to savings |
How it works
- Snowball
- Target = smallest remaining balance. Quick wins first.
- Avalanche
- Target = highest interest rate. Cheapest total cost.
- Cascade
- Any leftover pool after killing a target rolls to the next one, same month.
Interest accrues monthly at the entered annual rate / 12. The monthly budget stays fixed, including after a debt is paid off. Minimum payments are fixed amounts, not changing percentages. Unspent money goes to the selected target in the same month. No new borrowing, fees, or rate changes are modeled. Not reached means the debts were not cleared within 1,200 months, or no payments were available.
Worked example
A $1,200 medical bill at 0%, a $6,800 credit card at 24.99%, and a $12,000 car loan at 7.2%, with respective minimum payments of $50, $170, and $280 plus $300 extra a month: snowball finishes in 29 months paying $3,062.08 in interest; avalanche also takes 29 months but pays $2,749.46 — $312.62 cheaper for attacking the 24.99% card first.
Understanding your results
Compare the strategies using payoff order, time, and total modeled interest while keeping the same monthly budget. A result depends on the fixed minimums and rates entered. Actual creditors may change minimums, rates, fees, or payment allocation.
Sources and methodology
These resources explain related concepts. They do not certify or endorse this calculator. See the assumptions and worked example above.
- Debt reduction worksheet — CFPB ↗
Outlines the smallest-balance snowball and highest-interest-rate approaches and redirecting payments after a debt is paid.
Frequently asked questions
Snowball prioritizes the smallest remaining balance; avalanche prioritizes the highest rate. The calculator pays the entered minimums first in both cases. Compare the results with a repayment approach you can sustain.
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Open calculatorFigures are estimates for education only — not financial advice. Results depend on the assumptions you enter. Read the full disclaimer.