Debt Snowball vs Debt Avalanche

Two ways to direct extra dollars

The snowball method directs extra money to the smallest balance first while maintaining required payments on the other debts. The avalanche method directs extra money to the highest interest rate first. CFPB’s debt worksheet explains both priorities and the different motivations behind them.

In MoneyBasis, snowball uses initial balance order. Avalanche uses descending rate, then smaller balance to break a rate tie. Remaining ties keep the entered order. The priority is established at the start; it is not a new sorting of remaining balances every month.

This distinction matters because a payoff plan needs a reproducible rule. Otherwise, two schedules described with the same label could assign extra dollars differently. Neither ordering changes the need to meet the other debts’ minimums.CFPB

Minimums are part of one shared monthly budget

The monthly debt budget is the total available to all listed debts, not an extra amount added on top of every minimum. MoneyBasis first accrues monthly interest, reserves each active debt’s required minimum capped at its balance plus interest, and then directs the remaining dollars through the selected priority.

If an account is cleared before its allocated dollars are exhausted, the unused amount can go to the next account in the same month. Waiting until the following month would leave some of the stated budget unused and describe a slower plan. The final month spends only what is needed to clear the remaining debt; unused budget is not counted as an extra debt payment.

A budget below the required minimum total is not a feasible version of either method. Raising the priority of one account cannot justify failing to allocate the other accounts’ required payments. The calculator rejects an insufficient budget rather than manufacturing a successful payoff schedule.

Worked example

Worked example: three debts and $800 per month

Use a credit card with $4,200 at 19.9% and a $120 minimum; a personal loan with $3,500 at 12% and a $110 minimum; and a car loan with $11,000 at 6.5% and a $265 minimum. The fixed minimums total $495, leaving $305 of the $800 budget for priority payments at the start.

Snowball directs that initial extra amount to the personal loan; avalanche directs it to the credit card. Both keep paying the car loan minimum. The rates are fixed annual inputs divided by twelve, with payments following monthly interest. No new charges, fees or missed payments enter either scenario.

Both methods clear these particular debts in 26 months. Snowball incurs $2,075.23 of interest; avalanche incurs $1,883.84. Identical whole-month payoff counts therefore do not imply identical costs. The final partial payments differ.

Priority order and payoff order are not synonyms

Priority tells the model where to send extra money. Actual chronological payoff order records when each balance reaches zero after all payments. A lower-priority debt can clear early through its own minimum payments. It is therefore possible for a payoff timeline to differ from the initial extra-payment list.

The following tables show both concepts for the worked example, along with the first month’s allocation. The debt identities remain separate even if two accounts have the same display name. MoneyBasis tracks distinct account IDs so that clearing one account does not erase another account with a matching label.

A statement’s minimum may change as the balance changes. The example instead holds each entered minimum fixed, apart from capping the final amount due. That is part of the planning model and needs to be revisited when comparing its schedule with a real account.

Interest cost and follow-through are different considerations

Directing extra money toward a higher rate reduces exposure to that rate sooner. In this fixed-rate, fixed-budget example, avalanche has the lower interest total. That arithmetic does not establish which plan a particular person will maintain through changing income, competing bills or motivation.

Snowball emphasizes closing smaller balances, which can make progress visible sooner in some debt lists. It does not guarantee the first account will close faster in every possible comparison, and a psychological benefit cannot be measured by the interest engine. The behavioral question is separate from the modeled cost difference.

Comparing methods with different payment budgets obscures the ordering effect. A larger monthly payment can matter more than a modest difference in priority. A useful comparison holds the shared budget fixed first, then separately explores what a sustainable change in that budget would do.

Know when the schedule stops describing the debt

The engine assumes fixed rates, no new borrowing, no fees and regular monthly payments. It does not model promotional expiration, daily credit-card interest, variable rates, delinquency rules, settlements or lender-specific allocation across multiple balances on one account.

A payment that fails to cover interest can leave a balance growing. The result must not be read as a completed payoff merely because a simulation stopped. MoneyBasis limits this multi-debt simulation to 600 months and distinguishes payoff from a plan that remains unpaid at the horizon.

Payoff dates are estimates in calendar months under the entered schedule. They are not creditor payoff quotes. The useful output is the relationship among payment budget, priority, accrued interest and remaining balances under one explicit set of assumptions.