Avalanche vs Snowball on $13,500 Across Three Cards

When both orders agree on where to start

The $1,500 card at 27.99% is the most expensive balance on this sheet and also the smallest. That single coincidence collapses the usual disagreement: avalanche picks it because of the rate, snowball picks it because of the size, and for the opening stretch of the plan the two strategies are indistinguishable. They only part company at the second target, where avalanche moves to the $8,000 card at 21.99% and snowball moves to the $4,000 card at 15.99%.

Because they agree on the opening move and then differ only over the ordering of the two survivors, the plans can land on the same finishing month while still costing different amounts. This is the case people most often get wrong. Looking at a debt-free date and seeing no difference, they conclude the ordering question is settled and pick whichever feels better. But a payoff date is a coarse instrument. It rounds to whole months, and two schedules that clear within days of each other inside the same month report identically while having charged different amounts of interest along the way. The finish date is not the number that separates these plans; the interest total is.

This is also the one arrangement where the behavioural argument for snowball is close to free, and it is worth being precise about why. Normally the price of an early win is leaving a high rate running. Here the early win and the high rate are the same card, so you collect the motivation without paying for it. What remains is a second-order question about which of the two survivors to clear next, and the amount riding on that question is smaller than the amount riding on the opening move in a portfolio where the expensive card is large.

So the practical reading of this scenario is not that ordering does not matter. It is that ordering matters least when your rates and your balances happen to point the same way, and that you should check whether that is actually your situation before generalising from it. Move the 27.99% onto the $8,000 balance instead and this page becomes a different page entirely.

What the minimum payments do to the ordering decision

The minimums on these three cards are not proportional to their balances, and that asymmetry quietly shapes the comparison. The $8,000 card demands $200 a month, the $4,000 card demands $95, and the $1,500 card demands only $40. Whichever order you choose, those three amounts leave the $700 budget first, and only the remainder is aimed at a target.

That matters most at the moment a card retires, because what you gain is not the balance disappearing but the minimum being released back into the free portion. Retiring the $1,500 card frees $40. Retiring the $8,000 card frees $200 — five times as much, and it is that release, rather than the size of the balance, that determines how much the plan accelerates at each step. A card with a large balance and a large minimum is worth more to clear than its rate alone suggests, which is one reason snowball is not always as far behind as the arithmetic on rates would imply.

None of this is guesswork in the result you see. The engine charges interest on each card at its own rate first, pays every minimum second, and applies the leftover to a single target third, cascading into the next target within the same month if the current one clears early. Both orders are simulated under identical rules and identical inputs, so the only thing being compared is the sequence.

Worth trying: raise the $40 minimum on the small card and watch how little changes, then raise the $200 minimum on the large one and watch how much does. The minimums are where a portfolio's flexibility lives.

What a minimum payment actually is, and why it shrinks

A credit card minimum is not a fixed instalment. It is typically the larger of a small percentage of the current statement balance — commonly one to three percent, plus that month's interest and any fees — or a flat floor of around twenty-five or thirty-five dollars, whichever is greater. Because the percentage side is computed from the balance, the required minimum falls every month that the balance falls.

That is the trap, and it is designed rather than accidental. Paying the minimum feels like keeping up, but a shrinking payment against a balance that is still accruing interest at twenty-plus percent stretches the payoff over an extraordinary span. The typical illustration on a statement, which issuers in the United States are legally required to print, routinely shows a mid-four-figure balance taking somewhere between fifteen and thirty years to clear at the minimum, with total interest exceeding the original balance. The debt is not being retired; it is being maintained.

This calculator holds the minimum you enter flat for the life of the card rather than recalculating it downward each month. That is deliberate and it is the assumption that fits the tool's purpose. You are committing to a total monthly budget, not to whatever each issuer happens to demand, so a shrinking minimum would only reshuffle money between cards inside a total that never changes — and it would slightly understate the payoff date for anyone who does the sensible thing and keeps paying the same amount as the balance falls. Enter today's minimum from your statement and treat the figure as a floor, not a plan.

Balance transfers, promotional rates and the fee people forget

A zero percent balance transfer can beat any payoff order, because it attacks the rate rather than the sequence. Move a balance to a card charging nothing for eighteen months and every payment is principal for eighteen months. Nothing in avalanche or snowball comes close to that.

The catch is in the details, and there are three. First, the transfer fee, usually three to five percent of the amount moved, is charged up front and added to the transferred balance — five thousand moved at four percent is five thousand two hundred owed. Second, the promotional rate expires on a fixed date, and whatever balance remains on that date reverts to the card's ordinary rate, which is often higher than the one you left. Third, purchases made on the new card may not share the promotional rate at all, and payments are typically applied to the lowest-rate portion of the balance first, so a card used for spending during the promotion can accrue interest you did not expect.

The test is simple. Divide the transferred amount by the number of promotional months and ask whether you can genuinely pay that every month. If yes, the transfer is close to free money and this calculator understates what you can do. If no, model it as the rate you will actually be paying after the promotion ends, with the fee added to the balance, and compare that against staying put. This tool models no promotional periods and no fees at all — every rate you enter runs unchanged for the whole payoff — so a transfer is something to evaluate beside these numbers, not inside them.

Reading your result, and the cases where there is no answer

Three outcomes are possible and only one of them is a schedule. If your budget covers the minimums and the debt clears, you get a debt-free month count for each order, the interest each one costs, and the difference. If your budget is below the sum of the minimums, there is no plan at any order, and the page says so instead of producing a schedule that never terminates — the fix is more budget, a hardship arrangement with the issuer, or a consolidation, not a different ordering. If the minimums are covered but the interest still outruns the payments, the balance never reaches zero, and that is reported as such too.

The simulation is capped at a hundred years of months, and the cap can never be the reason you see a number: reaching it is reported as never clearing, and the partial totals are discarded rather than shown. A payoff plan that quietly truncates at some arbitrary horizon and prints a total is worse than no answer, because it looks like one.

Two habits make any of these numbers real. Stop adding new charges to the cards you are paying down, because new spending accrues at the same rate and silently resets the plan the calculator just built. And raise the budget rather than the effort: an extra fifty a month changes the result far more than any resequencing does, which is the quiet lesson of comparing avalanche against snowball and finding the gap smaller than you hoped.