Once you have more than one balance, you have a second decision on top of how much to pay: which account gets the extra money. The mechanics are the same either way — minimums on everything, all spare cash against one target, and when the target clears you roll its entire payment onto the next. Only the choice of target differs.

That choice has a name on each side and a small industry of people insisting theirs is correct.

Avalanche — the least interest

Order the accounts by interest rate, highest first, and attack the top one. Because interest accrues fastest where the rate is highest, killing that balance first starves the most expensive meter first.

This is the mathematically optimal order. It produces the earliest payoff date and the lowest total interest, and there is no arrangement that beats it on either measure. If the only thing you care about is the money, the conversation is over here.

Snowball — the earliest account closed

Order the accounts by balance, smallest first, and attack the top one regardless of its rate. The smallest balance clears soonest, so you get a finished account — and its whole payment rolling onto the next one — earlier than avalanche would give it to you.

It costs more. Usually not a great deal more, but more, and both in interest and in weeks. What you buy with that money is a completed thing, early, in a process whose defining problem is that it takes so long that people stop.

Which should you pick?

The useful question is not which is optimal — avalanche is — but how much snowball costs you, on your balances. That number ranges enormously. When the rates on your cards are close together, snowball is nearly free and you should probably take the early win. When one card is at a punishing rate and the rest are not, avalanche can be worth a meaningful sum and the discipline is worth finding.

So compute both, look at the gap, and then decide with the price in front of you. A plan you abandon in month seven has an infinite cost, and no spreadsheet models that. Neither method is wrong; being unable to see the trade-off is what is wrong.

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Both orders are simple enough to run in a spreadsheet, and always have been. The friction was never the maths — it was typing balances, rates, minimums and due dates for six accounts, and then keeping them current as you pay.

The calculator here runs both orders free, in your browser, with no account and no bank connection, and shows the difference in months and in dollars. Last Statement keeps that comparison accurate as you actually pay, and it is one payment of $39 — a debt tool should not become a bill. There are no ads in it, no lender referrals, and no refinance affiliates.

Educational, not financial advice. These comparisons assume fixed rates and on-time payments; your lender's terms control.