Debt Snowball vs Avalanche Calculator
Compare smallest-balance-first snowball and highest-APR-first avalanche payoff plans with a constant monthly budget.
Content updated August 3, 2026
| Strategy | Payoff time | Interest | Total paid | Final month |
|---|---|---|---|---|
| Snowball | 1 year, 10 months | $1,613.29 | $10,813.29 | $313.29 |
| Avalanche | 1 year, 10 months | $1,431.33 | $10,631.33 | $131.33 |
Snowball order: Store card (month 6) → Personal loan (month 13) → Credit card (month 22)
Avalanche order: Store card (month 6) → Credit card (month 19) → Personal loan (month 22)
Fixed-APR monthly model. It accrues APR ÷ 12 interest, pays every listed minimum, and rolls all freed payment capacity to the next target while keeping the total budget constant. It excludes new charges, fees, promotional-rate changes, daily interest, changing minimum formulas, and creditor allocation rules; compare the model with current statements before acting.
Debt snowball and debt avalanche use the same monthly budget but choose different targets for extra payments. Snowball sends the available extra amount to the smallest current balance; avalanche sends it to the highest APR. Both continue every other listed minimum payment.
Enter each debt on its own line with a name, balance, APR, and fixed minimum. The model accrues monthly interest, makes the minimums, and immediately rolls freed payment capacity to the next target so the total monthly debt budget remains constant until every modeled balance is paid.
The Debt Snowball vs Avalanche formula
Bᵢ,ₘ′ = Bᵢ,ₘ₋₁(1 + APRᵢ/12); budget = Σ minimumᵢ + extraEach month accrues modeled interest, pays active fixed minimums, and applies the remaining constant budget by smallest active balance for snowball or highest APR for avalanche.
Worked example
For balances of $5,000 at 20% with a $150 minimum, $3,000 at 10% with a $100 minimum, and $1,200 at 25% with a $50 minimum, plus $200 extra, the $500 monthly model pays both strategies in 22 months. The modeled snowball interest is about $1,613.29 and avalanche interest about $1,431.33.
Assumptions, rounding, and limitations
Assumptions
- Every debt uses the selected currency and one fixed balance, APR, and minimum payment at the start.
- Interest accrues once monthly at APR divided by 12 before that month's payments.
- The monthly budget equals the sum of original fixed minimum payments plus the entered extra amount and remains constant until payoff.
- No new purchases, advances, fees, missed payments, rate changes, or minimum-payment formula changes occur.
- Snowball prioritizes the smallest active modeled balance; avalanche prioritizes the highest APR, with documented deterministic tie handling.
Rounding: Balances, interest, and payments retain floating-point precision. Time is the first whole modeled month in which all balances reach zero, while displayed currency uses up to two decimal places.
Limitations
- Supports 1–20 debts, balances and payments up to 1 trillion each, APRs from 0% to 100%, and a maximum 1,200-month payoff horizon.
- The monthly-interest model does not reproduce daily balances, billing-cycle lengths, promotional or penalty rates, fees, multiple APR buckets, variable minimums, creditor posting order, delinquency, settlements, or consolidation terms.
- It is an educational scenario and not individualized credit, legal, tax, insolvency, or financial advice. Creditor statements and agreements control actual amounts.
Sources
- Reducing Debt Worksheet — Consumer Financial Protection Bureau
- How to Reduce Your Debt — Consumer Financial Protection Bureau
- How Credit Card Companies Calculate Interest — Consumer Financial Protection Bureau
Two priority rules, one controlled budget
The CFPB debt-reduction worksheet describes the highest-interest-rate method as paying the costliest debt first and snowball as paying the smallest debt first, then redirecting the entire freed payment to the next debt. This calculator implements those two priority rules against the same starting data and total budget.
Because minimums are paid before the targeted extra amount, a debt can finish during the minimum-payment step. Any unused portion of that minimum is available to the strategy target in the same modeled month rather than disappearing from the budget.
Why a statement can differ from the model
The comparison uses APR divided by 12 on the opening monthly balance. CFPB consumer guidance notes that many credit-card issuers instead calculate interest daily from average daily balances and can use different APRs or allocation rules for categories within one account.
Minimum payments can also change as balances, fees, or account terms change. Use the plan as a consistent comparison, then confirm current balances, minimums, rates, due dates, prepayment rules, and payment allocation with each creditor before sending money.
Frequently asked questions
▶What is the debt snowball method?
It pays all listed minimums and directs the remaining budget to the smallest current balance, rolling freed payments to the next smallest balance after payoff.
▶What is the debt avalanche method?
It pays all listed minimums and directs the remaining budget to the active debt with the highest APR, then moves to the next-highest APR.
▶Does avalanche always finish sooner?
Not necessarily in whole months. Under the model it often reduces interest, but final-payment timing and listed minimums can produce the same payoff month or other close outcomes.
▶How do I format the debt rows?
Use one line per debt in this order: name | balance | APR percentage | fixed minimum payment. Do not include currency symbols or percent signs.
▶Does the calculator change the minimum payment over time?
No. Each entered minimum remains fixed until that debt is paid. Real statement minimums can change, so update the inputs when your statements change.
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Open calculator →Disclaimer: Debt Snowball vs Avalanche Calculator results are estimates for general information and education only, and are not financial, tax, legal or medical advice. Verify important decisions with a qualified professional.