Debt Snowball vs Avalanche

How snowball and avalanche differ

The choice concerns extra-payment priority after the active accounts receive their required payments. The CFPB's reducing debt worksheet describes both approaches and redirecting a cleared debt's payment. Smaller-account wins may help some people sustain a plan; higher-rate targeting focuses on interest cost. Neither label establishes what a particular household will actually pay.

Start with the same debts and the same payment budget

The following accounts are hypothetical, with amounts in US dollars. Each has one constant interest rate and a fixed minimum. Both plans start with exactly these inputs, make end-of-month payments and add the same recurring extra amount. January 2027 labels the first monthly payment, not the borrowing date.

Here $P$ is total starting debt and $W$ is the monthly payment budget: initial minimums of $\$185$ plus $\$150$ extra. The full $\$335$ remains available as accounts clear, until the capped final payment. Changing that rollover rule changes the comparison. Use the Budget Percentage Calculator to check the cash flow supporting an extra payment.

Interest is calculated separately on each opening balance, rounded half up to cents, then added before payments. An exact half-cent rounds upward. The model pays each capped fixed minimum first and allocates the remaining pool by priority. For equal priority values it uses the other ranking measure, then input order. Actual card minimums and daily interest can differ; this is an intentionally reproducible monthly model.

Step by step: the first monthly payment

1. Calculate each account's interest

For account $j$ in month $t$, let $B_{j,t-1}$ be its opening balance and $a_j$ its annual rate entered as a numerical percentage. The monthly rate is $i_j=a_j/1200$. In this model:

Both strategies incur the same first-month interest of $\$82.50$: the balances are equal before the first payment. The allocation affects the next month's opening balances. The APR vs APY guide explains rate conventions; a fee-inclusive installment-loan APR is not automatically the periodic accrual rate.

2. Apply minimums, then direct the extra pool

Snowball puts the $\$150$ extra toward Account A, whose scheduled minimum is $\$25$. Avalanche puts it toward Account B, whose minimum is $\$60$. Account C receives $\$100$ in both plans this month.

3. Carry the remaining balances into the next month

Here $p_{j,t}$ is the actual payment, capped at the amount owed. The two plans have the same combined closing balance, $\$6{,}247.50$, after month $1$. Its distribution differs: avalanche leaves less at the higher rate. In month $2$, snowball incurs $\$80.64$ interest and avalanche $\$78.39$.

What payment rollover actually does

In the snowball schedule, Account A opens month $3$ at $\$154.14$. Its rounded interest is $\$0.77$. The available $\$175$ payment is more than it needs, so the calculator pays only the remaining amount and directs the unused part to B in the same month.

In month $4$, A needs no payment. B receives its original minimum, A's freed minimum and the recurring extra: $60+25+150=\$235$. C still receives $\$100$, so the total remains $\$335$. This is a redirection of the existing budget; it does not create an additional source of money.

Confirm the actual amount required to close an account and the payment posting date. A lender may accrue interest daily or apply payments under contract-specific rules. The amortization guide explains the distinction between a modeled closing balance and a dated payoff quote.

Compare the full schedules, not just the first win

The calculator links preserve all inputs. Its CSV includes both complete ledgers and per-account payments; its print view can save the schedule as PDF. On mobile, swipe a wide table or focus it and use the arrow keys. Long formulas support the same keyboard scrolling. Expand practice answers before printing this reference if you want the solutions included.

Why paying the higher rate can reduce interest

For the next unrounded monthly interest calculation, moving an extra amount $E$ from reducing a low-rate balance to reducing a high-rate balance changes the interest by $E(r_h-r_l)/12$, provided both balances can absorb the payment and the annual rates are decimals. In this example:

That matches the second-month difference, $80.64-78.39=\$2.25$, after the first payment allocation. It is a one-period explanation, not a formula for the whole loan's savings. Balances, payment caps and the priority pool change as accounts clear, so the full $\$70.40$ comparison comes from all monthly rows.

A rate ranking is most useful when the relevant rates, costs and future payment resources are comparable. An account with a larger opening balance can initially generate a larger dollar interest charge despite having a lower rate; the marginal cost of leaving an additional dollar outstanding depends on its rate.

When the strategies agree

Keep the same balances, fixed minimums and extra amount, but set A's rate to $24\%$, B's to $12\%$ and C's to $6\%$. Both strategies then allocate payments identically in this example: $21$ months and $\$451.28$ total interest. Check the aligned-priority example.

If all three rates are zero, total interest is zero and both plans finish in $20$ months at this budget, although individual accounts can close in a different order. There is no rate-cost advantage to capture. Open the zero-rate comparison.

Keep the strategy comparison separate from the budget decision

Increasing the recurring extra from $\$150$ to $\$200$ changes the total budget from $\$335$ to $\$385$. Holding every other main-example input fixed, snowball then finishes in $19$ months with $\$800.10$ interest; avalanche finishes in $19$ months with $\$737.55$ interest.

With no recurring extra, the initial minimums still create a constant $\$185$ rollover budget in this calculator. Both methods happen to produce the same $48$-month schedule and $\$2{,}251.08$ interest here. Until an account clears there is no extra pool to allocate; afterward both priorities agree. This is a fixed-budget comparison, not a forecast of a lender's declining minimum-only bill. Inspect the no-extra rollover case.

A useful personal comparison changes one decision at a time. First compare priorities at a repeatable budget; then compare affordable budget amounts. A larger hypothetical payment is not an improvement if income and essential expenses cannot support it. The Emergency Fund Calculator can help examine the cash reserve alongside the repayment budget.

Check these details before applying an ordering rule

Daily interest and new spending

The CFPB daily-rate explanation describes how card interest may depend on daily balances. Payment dates, changing rates, new purchases and fees require additional inputs. The Credit Card Payoff Calculator can explore ongoing charges for one card; it is a separate comparison from the fee-free monthly accounts here.

Several balances within one card account

Choosing which account to pay is different from the issuer allocating a payment among purchase, transfer or cash-advance balances inside that account. In the US, Regulation Z payment allocation generally directs amounts above the required minimum to a higher-rate balance on a covered account, with exceptions. That provision does not specify how the required minimum itself must be allocated. These US sources should not be assumed to govern every jurisdiction.

Promotional deadlines and other obligations

A deferred-interest deadline can make a simple current-rate ranking incomplete. The CFPB deferred-interest guide explains the potential charge reaching back to the purchase and why minimum payments may not clear it in time. Record the actual promotion and allocation rules. The examples do not price that contingent cost, secured-debt consequences, legal obligations or forgiveness eligibility.

If required payments are unaffordable

Do not use an extra-payment ranking to skip required payments elsewhere. Follow the CFPB guidance on payment difficulties: contact the issuer promptly, explain the amount you can afford and ask about available arrangements. Credit counseling may help evaluate the whole situation. A modeled payoff date does not resolve a current cash-flow shortfall.

Make the choice measurable

1. List balances, applicable rates, required payments, due dates and any deadlines.
2. Set a total budget that can continue while accounts clear.
3. Run both priorities from the same starting balances and assumptions.
4. Compare interest, first closure, final payment date and any unpaid balance.
5. Reconcile posted payments monthly; document the reason for a change or hybrid.

Check your understanding

Work through each question, then open its solution. These answers remain usable without JavaScript.

Sources and verification method

These primary references support the method and product distinctions. The hypothetical amounts, complete ledgers and three chart geometries were checked independently with exact one-period algebra and a decimal monthly schedule, including rounding and payoff caps. They describe this model rather than a current lender offer.

• CFPB: Reducing debt worksheet

  Defines smallest-balance and highest-interest approaches and rolling a cleared debt's payment into the next target.

• CFPB: Daily periodic rates on credit cards

  Explains daily interest timing, which can differ from the equal-month model used in the examples.

• CFPB: Regulation Z, allocation of payments

  The US rule generally concerns amounts above the minimum within a covered card account, with exceptions; it is not a rule selecting which separate account you pay.

• CFPB: Deferred-interest purchases

  A deferred-interest deadline and allocation rules can change the practical priority; a low current rate alone is insufficient.

• CFPB: If you cannot pay your credit card bills

  Contact the issuer promptly, explain what you can afford, and consider credit counseling when minimums are unaffordable.

Explore the payment plan behind the comparison

• Debt Payoff Calculator
• Credit Card Payoff Calculator
• Budget Percentage Calculator
• Emergency Fund Calculator
• How Amortization Works
• APR vs APY