Debt snowball vs. avalanche calculator

Key takeaway: Snowball and avalanche spend identical dollars each month — you're only choosing which debt soaks up your spare money first. That choice sets your total interest bill and how soon the first balance disappears.

You're here because you owe on more than one account — a store card, a Visa, a car loan — and each statement wants its own minimum. This calculator answers the question the statements never do: once every minimum is covered, where should the rest go? List each debt with its balance, APR, and minimum payment, set one total monthly budget, and compare the two classic orderings side by side. Carrying just one balance? Ordering doesn't apply — the credit card payoff calculator is built for that.

Two orders, one budget

The monthly routine is identical under both strategies: every debt gets its minimum payment, and the entire remainder of your budget lands on a single target. Snowball targets the smallest balance, ignoring rates; avalanche targets the highest APR, ignoring size. The ranking is fixed up front from your opening numbers and never reshuffled.

What makes either version work is the rollover. When the target hits zero, its payment — minimum plus extra — moves to the next debt in line instead of returning to your pocket. Your total outlay never changes; the share aimed at the current target keeps growing, which is why the last debts fall faster than the first even though you never paid a dollar more.

What the default numbers show

The calculator opens with three debts — a $1,400 store card at 26.9% APR ($40 minimum), a $900 Visa at 21.4% ($30 minimum), and a $9,500 car loan at 7.2% ($220 minimum) — $11,800 in total against a $500 monthly budget. Minimums claim $290, leaving $210 of extra, and the two strategies disagree about where it belongs.

The interest formula underneath is one line: each month, every open debt is charged its balance times its APR divided by twelve, before payments land. In month one the store card accrues $1,400 × 26.9% ÷ 12 ≈ $31.38, the Visa $16.05, and the car loan $57.00 — $104.43 across the three.

Snowball aims the $210 at the Visa: gone in month 4, store card in month 10, car loan in month 26, with $1,175.40 of interest paid along the way. Avalanche aims it at the store card: cleared in month 7, Visa in month 10, car loan again in month 26 — $1,153.97 in total interest. Same 26-month finish either way; avalanche arrives $21.43 cheaper.

The case for each order

Avalanche's argument is arithmetic: spare dollars aimed at the highest APR shut down the fastest-growing interest first, so no other ordering of the same budget can cost less. The edge is real money when rates span a wide range — card APRs currently average 24.35% while auto and personal loans often run in the single digits.

Snowball's argument is that a plan only saves money if you finish it. Quitting halfway is the most expensive outcome on the menu — costlier than any suboptimal ordering — and a whole account hitting zero is the kind of proof that keeps people paying. Here, snowball delivers that first win in month 4 instead of month 7, and the head start costs about the price of a pizza spread over two years. If you've abandoned payoff plans before, buy the momentum; if the spreadsheet is motivation enough, take the discount.

When the choice barely matters

The two orders converge when your APRs sit close together. The default cards are about five points apart, and the entire disagreement is worth $21.43 — a rounding error against $11,800 of debt. In that case, pick snowball without guilt; the math you're giving up is trivial.

The gap widens when one rate towers over the rest — a penalty-APR card next to a 7% auto loan, say — and grows further when the high-rate balance is large, since it compounds while waiting its turn. If your smallest balance also carries your highest APR, both strategies pick the same target and there's no decision at all. If every rate on the list is painful, sequencing may be the wrong lever: the balance transfer breakeven calculator checks whether a 0% window beats attacking the balance in place.

How we calculate this

We rank your debts once, from the inputs as entered — ascending balance for snowball, descending APR for avalanche. Each simulated month, every open debt accrues interest at one-twelfth of its APR on its current balance and receives its minimum payment; whatever budget remains goes to the highest-ranked open debt, spilling to the next rank if the target needs less. A cleared debt drops out, freeing its minimum from the following month. The run ends when the last balance clears; totals are straight sums of every payment and interest charge. If your budget sits below the combined minimums, no order can work — the calculator says so rather than showing an impossible payoff date.

Frequently asked questions

What's the difference between snowball and avalanche?

Snowball ranks your debts from smallest balance to largest and clears whole accounts quickly. Avalanche ranks them from highest APR to lowest, so your spare dollars always fight the most expensive interest. Avalanche never costs more in total interest; snowball is often easier to stick with.

What happens to a debt's payment once it's paid off?

Its full monthly claim — minimum plus any extra it was absorbing — rolls forward to the next debt in your order. Your total outlay never shrinks until the last debt is gone, which is why the later payoffs happen so much faster than the first.

What if my budget doesn't cover all my minimum payments?

Neither strategy can run below the minimums — you'd fall behind on at least one account no matter the order. Raise the budget above your combined minimums, or talk to your issuers about hardship programs before worrying about sequencing.

Does the payoff order change as my balances shrink?

No — the ranking is set once from your starting balances and APRs. Avalanche loses nothing, since APRs don't change as you pay; under snowball the debt being attacked shrinks fastest, so it almost always stays the smallest anyway.

Should I include debts like my car loan, or only credit cards?

Include anything with a balance, an APR, and a fixed minimum — car loans, personal loans, medical payment plans, store cards. The comparison is most useful when your list mixes high and low rates, since that's where the two orders disagree. Most people leave a mortgage out: its size swamps the timeline, and prepaying one is a separate decision.

Sources

• Federal Reserve, G.19 Consumer Credit release (Federal Reserve G.19 Consumer Credit report, as of 2026-05-01)
• Consumer Financial Protection Bureau, Credit cards