Avalanche vs snowball
You have several credit-card balances and a fixed amount to throw at them each month. The math says pay highest APR first (avalanche). The behavioral research says pay smallest balance first (snowball) — because the first card paid off is a win you can feel, and momentum keeps you on the plan. Both beat paying minimums. The dollar delta between them is the price of psychological motivation — usually small, sometimes worth it.
Last updated 2026-05-13
- 1. Store card6 mo
- 2. Visa1 yr 6 mo
- 3. AmEx2 yr 7 mo
- 1. Store card6 mo
- 2. Visa1 yr 6 mo
- 3. AmEx2 yr 7 mo
MethodologyHow the simulation works, and which strategy to pick
How the simulation works, and which strategy to pick
The mechanic both strategies share:every month, pay the issuer minimum on every card (otherwise late fees and credit-score hits wipe out any optimization). Then take whatever's left of your monthly budget and apply it all to one "priority" card. When that card pays off, redirect its minimum + the extra to the next priority. Repeat until debt-free.
Avalanche:priority = highest APR. Mathematically optimal — you're always attacking the dollar that grows fastest. Total interest paid is the lowest theoretically achievable for a given monthly budget. Downside: the highest-APR card often has the largest balance, so it takes longest to clear → no early win, motivation can fade.
Snowball:priority = smallest balance. The first card pays off fastest because there's the least to clear. That early win is a psychological tailwind — studies (notably the 2018 Boston Consulting Group research on consumer debt) show people are more likely to stay on the plan when they see fast progress. Pays slightly more interest because you might be ignoring a high-APR card while you knock out a low-APR small one.
The dollar delta varies wildly. If your smallest-balance card is also your highest-APR card (often the case for store cards), the two strategies converge — same payoff order, same math. If they diverge (large high-APR card + small low-APR card), avalanche can save real money. The calculator surfaces the exact figure so you can decide if the motivation effect is worth that dollar amount to you.
The honest decision rule:pick the strategy you'll actually finish. A snowball plan you complete beats an avalanche plan you quit halfway through. If you've started and stopped before, snowball is probably worth the extra interest. If you're analytical and don't need motivational milestones, avalanche.
Hybrid "debt fireball": snowball for tiny balances ($500 or less — quick win), then avalanche the rest. Captures the motivation effect once, then minimizes total interest. Not modeled explicitly here but easy to mimic: solve snowball first, see when the small card clears, then mentally re-prioritize remaining cards by APR.
What we deliberately don't model: balance-transfer APR promos (often game-changers — a 0% intro on the largest card can beat any payoff order); APR changes mid-payoff (variable cards); fee stacks (annual fees, late fees, returned-payment fees); changing minimum-payment formulas across issuers; new charges added during payoff. The simulation assumes you stop adding to balances. If you keep charging, no payoff strategy works.
If your budget is below the sum of minimums:the calculator flags this and stops. Falling below minimums triggers late fees and damages credit — worse than any payoff order. Priorities: raise the budget, consolidate to a balance-transfer card, contact issuers for hardship terms, or as a last resort consult a non-profit credit counselor (NFCC member agencies, not for-profit "debt relief" companies — those are usually scams).