Which method is mathematically better?

Avalanche, always — paying the highest interest rate first minimizes total interest by definition. The comparison above shows exactly how much it saves on your debts. When the rates are close together, the difference can be surprisingly small.

Then why does anyone choose snowball?

Because paying off debt takes years, and quick early wins help people persist. Snowball clears the smallest balances first, shrinking the number of open accounts fast. If seeing accounts hit zero keeps you paying, snowball's extra interest can be a fair price for actually finishing.

How does the simulation work?

Each month, every debt accrues one month of interest at its APR, minimum payments go to every debt, and your extra payment — plus minimums freed by paid-off debts — attacks the priority debt for the chosen strategy. It runs until everything hits zero and reports the months and total interest for each method.

What if the calculator says my balances never shrink?

Then your combined payments don't cover the monthly interest — the debt is compounding against you. Priorities become: stop new borrowing, look at rate reductions (balance transfers, consolidation, hardship programs), and raise the monthly payment even modestly. Small increases matter enormously near the break-even point.

Debt Payoff Calculator — Snowball vs Avalanche, Compared on Your Debts

Debt Payoff Calculator: Snowball vs Avalanche

List your debts, set your extra payment, and see both classic strategies simulated side by side — months to debt-free and total interest for each.

DebtBalance$APR%Min payment$

$%$

Extra payment per month$

Avalanche (highest rate first)

Debt-free in: 2 yr 3 mo
Total interest: $1,513

Snowball (smallest balance first)

Debt-free in: 2 yr 3 mo
Total interest: $1,513

For your debts the two methods cost nearly the same — pick the one that keeps you motivated.

Same debts, two orders, different price

With multiple debts, minimum payments keep you afloat — the extra dollars decide how fast you escape and what you pay for the trip. The two classic orders: avalanche attacks the highest interest rate first and minimizes total interest; snowball attacks the smallest balance first and maximizes early wins. This calculator runs both on your actual debts so the trade-off is a number, not a debate.

What the numbers mean

Debt-free in — months until the last balance hits zero, holding your total monthly payment constant.
Total interest— what the debt costs you beyond repaying the principal. The gap between methods is avalanche's saving.

How to use the result

If avalanche's saving is large, take it. If it's small, choose whichever order you'll actually sustain — an abandoned avalanche loses to a finished snowball. And notice the third lever the comparison quietly reveals: raising the extra payment even slightly usually beats either ordering. Re-run the numbers whenever a debt closes; the freed minimum is a raise you give your payoff plan.

A quick example

Start with the example already in the calculator: a $4,000 credit card at 22% APR with a $100 minimum payment, plus a $9,000 car loan at 7% with a $250 minimum. Add $200 per month above those minimums. The avalanche directs that extra money to the card first because its rate is higher; the snowball directs it to the smaller balance first. Once one balance reaches zero, its former minimum payment rolls into the next target in both plans. Change every number to match your actual statements before relying on the comparison.

What this model assumes

The calculator adds one month of interest using APR ÷ 12, makes every minimum payment, then directs all remaining budget to the chosen target. It holds your rates, minimums, and total monthly budget constant. Real accounts may use daily interest, change a minimum payment as the balance falls, charge fees, offer a temporary APR, or have rules for extra payments. It also cannot account for new charges, missed payments, taxes, refinancing costs, or the effect a repayment plan may have on credit. Treat the dates and interest totals as useful estimates, not lender payoff quotes.

Sources and next steps

The Consumer Financial Protection Bureau describes the same two basic approaches: highest-interest-first to reduce long-run cost, and smallest-balance-first to create visible momentum. If minimum payments are unaffordable or your balances are growing, contact your lender or a qualified nonprofit credit counselor before choosing a plan. This calculator is educational information, not personalized debt, credit, or legal advice. Read the CFPB's debt-reduction guide for a plain-language comparison of both methods.

Worked decision guide

Debt Snowball vs. Avalanche: A Worked Example

Follow the first payments of both debt strategies, understand why their totals differ, and choose without relying on slogans.

Read the worked example

Frequently asked questions

Which method is mathematically better?: Avalanche, always — paying the highest interest rate first minimizes total interest by definition. The comparison above shows exactly how much it saves on your debts. When the rates are close together, the difference can be surprisingly small.
Then why does anyone choose snowball?: Because paying off debt takes years, and quick early wins help people persist. Snowball clears the smallest balances first, shrinking the number of open accounts fast. If seeing accounts hit zero keeps you paying, snowball's extra interest can be a fair price for actually finishing.
How does the simulation work?: Each month, every debt accrues one month of interest at its APR, minimum payments go to every debt, and your extra payment — plus minimums freed by paid-off debts — attacks the priority debt for the chosen strategy. It runs until everything hits zero and reports the months and total interest for each method.
What if the calculator says my balances never shrink?: Then your combined payments don't cover the monthly interest — the debt is compounding against you. Priorities become: stop new borrowing, look at rate reductions (balance transfers, consolidation, hardship programs), and raise the monthly payment even modestly. Small increases matter enormously near the break-even point.