Debt Snowball vs Avalanche Calculator

Michael Whitman · Trading since 2017, full-time since 2020 · Published 2026-10-14

The debt snowball vs avalanche question is about where your spare money goes each month. The snowball sends it to the smallest balance first. The avalanche sends it to the highest interest rate first. Everything else, including the total you pay each month, stays the same.

On this calculator’s defaults, the avalanche wins by $211 and the snowball wins the first finish line.

How the number is built

The calculator runs a month-by-month race, not a formula. Each month it adds interest to every open balance, at the yearly rate divided by 12. Then it pays every debt its minimum. Whatever is left of your monthly total goes to the target debt.

Your monthly total never changes. It is your extra amount plus the minimums of every debt you start with. When a debt hits zero, its minimum does not disappear. It rolls into the next target, which is why the payments seem to snowball even under the avalanche order.

The two methods differ only in the order of targets.

• Snowball: smallest starting balance first. A tie goes to the higher rate.
• Avalanche: highest interest rate first. A tie goes to the smaller balance.

If money is left over after a debt is cleared mid-month, it spills to the next debt in line that same month. The calculator counts the months until all three balances reach zero and adds up every dollar of interest charged on the way.

A worked example

The defaults are three ordinary debts, with interest rates taken from the Federal Reserve. The Fed’s G.19 consumer credit release for August 2026, published 7 October 2026, lists 22.36% on credit card accounts that were charged interest, 11.90% on 24-month personal loans and 7.54% on 60-month new car loans at commercial banks.

The second sources are close. Bankrate’s weekly card average was 19.65% for the week of 7 October 2026, and its personal loan average was 12.54% on the same date. Experian put the average new car loan at 6.35% for the second quarter of 2026, in its report covered by Auto Remarketing on 27 August 2026.

The balances and minimums are our assumptions, chosen to look like one household:

• a credit card with $7,000 at 22.36% and a $210 minimum (3% of the balance)
• the last $5,000 of a car loan at 7.54%, with its $360 payment
• a personal loan with $9,000 at 11.90% and a $300 payment
• plus $200 a month on top, for a monthly total of $1,070

In month one the three balances run up $251.10 of interest: $130.43 on the card, $31.42 on the car and $89.25 on the personal loan. More than half of it comes from the card.

The snowball aims the extra $200 at the car loan, the smallest balance. The car drops from $5,000 to $4,471.42 after one month and is gone in month 10. Its $560 then joins the card’s $210, so the card is cleared in month 19 and the personal loan in month 23.

The avalanche aims the $200 at the card, the highest rate. The card falls to $6,720.43 after one month and is gone in month 18. The car loan finishes on its own payment in month 15, and the personal loan again lasts until month 23.

The snowball pays $3,296 of interest and the avalanche pays $3,085. The gap is $211, about 6% of what the snowball pays, and neither method finishes even a month sooner. The chart below shows the order each method clears the three debts.

When the snowball is the better choice

The interest math favored the avalanche in every run on this page, and the research on real people gives the snowball a real case. Two studies are worth knowing.

David Gal and Blake McShane studied nearly 6,000 clients of a debt settlement firm in a 2012 Journal of Marketing Research paper titled “Can Fighting Small Battles Help Win the War?”

The clients did not choose which creditor was paid first. That let the authors compare people who had closed more accounts with people who had paid off a similar share of dollars. Kellogg Insight’s 2014 summary says the share of accounts closed predicted finishing the program better than the share of dollars repaid. The researchers also warn that the two measures move together and are hard to pull apart.

Keri Kettle, Remi Trudel, Simon Blanchard and Gerald Häubl reached a similar answer in 2016. Their Journal of Consumer Research paper combined credit data from about 6,000 Americans with controlled experiments.

The University of Alberta’s write-up reports that people who put their payments toward one card at a time paid down their card debt 15% faster than people who split payments evenly. The effect was strongest when the focus was the smallest account. Trudel wrote about how to split repayments across cards for Harvard Business Review in December 2016, and the St. Louis Fed’s Page One Economics cites that article in support of the “quick wins” idea.

Read both carefully. The 15% figure compares one account at a time with spreading money evenly, not snowball with avalanche. And the settlement study measures who finished, not who paid the least interest.

So the snowball is the better choice when quitting is the real risk. If a paid-off account in month 10 is what keeps you paying until month 23, it is worth more than $211.

Dave Ramsey builds his plan on that idea. Ramsey Solutions’ Baby Step 2 is to pay off all debt except the house with the debt snowball, smallest balance to largest regardless of rate.

Reading your result

A saving under about $100 means the order barely matters for you. Pick the method you like and spend your effort on the extra amount instead.

A saving in the thousands means a big balance is carrying a high rate. That is the case where the snowball’s early win is expensive, and it is worth checking whether a lower-rate refinance or balance transfer exists before choosing either order.

A “months sooner” result of zero is common. Both methods send the same total every month, so they tend to finish together. The difference shows up as interest, not time.

The original data

We ran the calculator’s own engine on 13,500 mixes of three debts. Each mix has three debts. Each balance is $1,000, $2,500, $5,000, $10,000 or $20,000; each rate is one of the three Fed August 2026 rates above (7.54%, 11.90% or 22.36%); and the extra amount is $0, $100, $250 or $500 a month. Each minimum is set to that debt’s first month of interest plus 2% of its balance. Every combination of the three input rows is counted, so the same three debts entered in a different order count as separate mixes.

In 6,300 of the 13,500 mixes the two methods pick the same order, because the smallest debt also carries the highest rate, so there is nothing to compare. The results below cover the other 7,200.

• The avalanche cost less interest in 5,700 mixes and tied in 1,500. The snowball cost less in none.
• The median saving was $149, about 4.8% of the snowball’s interest. The 90th percentile was $681.
• 40% of mixes saved under $100, ties included. Only 270, or 3.75%, saved $1,000 or more. In between, 1,389 mixes saved $0.01 to $99, 1,788 saved $100 to $249, 1,269 saved $250 to $499 and 984 saved $500 to $999.
• The largest saving was $1,972, on a $20,000 balance at 22.36% next to two $10,000 balances at 7.54%, with $500 extra. That is 24% of the snowball’s $8,083 of interest.
• Both methods finished in the same month in 5,388 mixes (75%). The avalanche finished sooner in the rest, never by more than 2 months.
• The snowball paid off its first debt sooner in 3,942 mixes (55%), by a median of 3 months across all 7,200, and never later.

The size of the saving follows the gap between rates. When the mix only spans 7.54% and 11.90%, the median saving was $71. Between 11.90% and 22.36% it was $174. When it includes both the 7.54% loan rate and the 22.36% card rate, it was $205. With $0 extra the median was $0, because the order only matters once a debt is paid off and its minimum starts to roll.

The full grid, one row per mix, is in the data file.

When it fails

New spending breaks every number on this page. The calculator assumes no new charges. A card you keep using is not on any payoff schedule.

Minimums are held fixed. Many card minimums are a percentage of the balance, so they shrink as it falls and payoff slows. Hold your payment at today’s level to match the calculator.

Rates change. Most card rates are variable, and a promotional 0% rate that ends turns a cheap debt into an expensive one mid-plan.

The model charges interest monthly on the balance. Many card issuers charge interest daily, so your statement interest can differ by a few dollars a month.

Emptying your savings to speed this up can backfire. Without an emergency fund, the next surprise bill goes back on the card.

And no calculator measures motivation. The research above suggests the snowball helps some people finish. It cannot tell you whether you are one of them.

Related

The paying off debt page weighs the order against simply raising the monthly payment. Credit card interest explains how the APR in the first box is charged. Our Dave Ramsey page checks the rest of his Baby Steps. For the step after the debt is gone, the compound growth calculator shows what the same monthly payment becomes when it is invested instead.

This page is educational, not financial advice. Test every idea on your own charts before risking money.