Debt Payoff Calculator: Snowball vs. Avalanche

Snowball vs. avalanche: what the two methods actually do

Both methods assume the same thing - you pay minimums on everything, then throw every spare dollar at one target debt. They differ only in which debt you target first.

Avalanche targets the highest interest rate first. This is mathematically optimal. It always produces the lowest total interest paid and, usually, the fastest payoff date.

Snowball targets the smallest balance first, regardless of rate. You clear individual debts faster, which produces visible wins early.

Which one should you actually use?

The honest answer is that avalanche wins on paper and snowball wins on follow-through, and the gap is often smaller than people assume.

Consider three debts:

With $700/month total:

• Avalanche attacks the credit card first - the 24% is bleeding you at roughly $160/month in interest alone.
• Snowball clears the $1,200 medical bill in about two months, freeing its $50 minimum and delivering a completed debt early.

Avalanche might save you a few hundred dollars over the full payoff. Snowball might be the reason you're still doing this in month seven. Research on consumer debt repayment has repeatedly found that people using the snowball method are more likely to stay with the plan - and a slightly suboptimal plan you finish beats an optimal one you abandon.

A reasonable hybrid: if you have one or two tiny balances, clear them first for momentum, then switch to strict avalanche for everything remaining.

Whichever you pick, the number that decides the timeline is the one you can put in every month. If you're not sure what that is, start from take-home pay with the paycheck calculator rather than from salary.

Why credit card minimum payments are a trap

Most issuers calculate the minimum as roughly 1% of the balance plus the interest accrued that month, with a floor around $25–35. The structure guarantees that most of your payment covers interest and very little touches principal.

Take an $8,000 balance at 24% APR:

Paying the minimum costs nearly twice the original balance in interest and takes over two decades. The same debt, with a payment most people could reach by redirecting one or two subscriptions, clears in a little over two years.

Here's the part that should alarm you. Some cards set the minimum at a flat 2% of the balance with no interest add-on. At 24% APR, monthly interest is exactly 2% - so on an $8,000 balance, a $160 minimum payment is met entirely by the $160 of monthly interest. The balance never moves. Not slowly: never. Anyone paying a flat-percentage minimum on a high-APR card can make payments forever and owe the same amount.

The lesson isn't subtle: the minimum shrinks as your balance does, which is precisely what extends the timeline. A fixed payment above the minimum is what actually ends the debt.

Before you start either method

• Stop adding to the pile. A payoff plan running alongside continued credit card spending is just treading water.
• Keep a small emergency buffer. $500–1,000 set aside prevents the next flat tire from going back on the card and undoing three months of progress.
• Check whether a balance transfer helps. A 0% intro APR card can pause interest for 12–21 months, but weigh the 3–5% transfer fee and be certain you'll clear it before the promotional rate expires - the APR calculator turns that fee into an effective rate you can compare directly against the debt you're moving.
• Don't drain retirement to pay consumer debt without understanding the taxes and penalties - early withdrawal typically costs income tax plus a 10% penalty, which can exceed the interest you're trying to escape.

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