Same three debts, same $700 a month, two different orders — and a real, countable difference: $278.90 of interest, and a first victory that arrives either in month 7 or in month 17. This is the snowball–avalanche argument settled the only way it can be, with one fixed set of debts run both ways and every month counted.

The test set

Comparisons of payoff methods usually fail before they start, because each side quietly picks debts that flatter it. So here is one set, fixed for the whole article: a credit card, a personal loan and an auto loan, chosen because their sizes and their rates pull in opposite directions — the smallest debt is not the most expensive one, which is exactly the situation that makes the two methods disagree.

The test set: $19,900 of debt, $700 a month. Month 1 minimums total $495.96, leaving $204.04 of spare money to aim.

Both plans obey identical rules. Every debt receives its minimum each month. The spare money — $204.04 in month 1, growing as minimums shrink and debts die — goes to a single target, and when a target is paid off its entire payment rolls to the next debt in the same month. The only difference between the two runs is which debt is the target. Everything below was computed with the Debt Payoff Calculator and checked against an independent month-by-month simulation; the two agreed to the cent.

What is the debt snowball method?

What is the debt snowball method, in one sentence? Rank the debts by balance, smallest first, and aim every spare dollar at the smallest — regardless of its interest rate. On the test set that order is Personal Loan → Credit Card → Auto Loan. In month 1 the personal loan receives $289.04 (its $85 minimum plus the whole $204.04 of spare money) and falls to $1,627.57, while the card and the auto loan get minimums only.

The snowball debt payoff then produces its signature moment in month 7: the personal loan reaches zero. One debt is simply gone — one fewer statement, one fewer minimum to juggle — and the card, still standing at $4,383.46, inherits the full roll-down. The card clears in month 19 and the auto loan, fed by everything, in month 33. The price of those early celebrations is printed in the milestone table below: $3,112.60 of interest, because the most expensive balance on the page waited seven months for its first extra dollar and nineteen months to die.

The snowball’s first seven months. The personal loan takes every spare dollar and dies in month 7; the card, on minimums only, shrinks by roughly $47 a month — until the cascade reaches it.

Watch month 7 closely, because it shows the machinery a tracker has to get right. The personal loan opens that month owing $205.92; after its interest and minimum it needs only $122.72 of the spare money to die — and the remaining $90.45 does not wait for month 8. It cascades onto the credit card in the same month, which is why the card’s balance drops by $135.64 in month 7 instead of its usual $46 or so. Any spreadsheet or app running this plan has to reproduce that cascade faithfully; miss it, and every projection after month 7 is flattered.

The avalanche debt method, same debts

The avalanche debt method ranks by price instead of size: highest APR first, no exceptions. Any debt avalanche calculator — this one included — therefore targets the 26.99% credit card from month 1, sending it $360.00 in the first month while the personal loan and auto loan sit at their minimums. The card dies in month 17, and then the story surprises people: the personal loan follows in month 18, just one month later, because the card’s freed payment cascades onto it at full force. The auto loan closes in month 33, exactly as it did under the snowball.

Same debts, same budget, both schedules produced by the Debt Payoff Calculator. The avalanche saves $278.90; the snowball banks its first win ten months sooner.

Read the table as a price list. The avalanche costs $278.90 less and finishes in the same month. The snowball’s first win arrives ten months earlier. Those are the two honest facts of this comparison, and every avalanche debt method calculator comparison on any other debt set will produce its own version of the same two facts — a sum of money on one side, a date on the other.

When the gap grows — and when it vanishes

The $278.90 gap is not a property of the methods; it is a property of these debts. Three things stretch it. A wide rate spread: the wider the gap between the dearest APR and the rest, the more each misdirected month costs. A large expensive balance: the card here is $4,800 — had it been $14,800 at the same rate, the snowball’s seven-month delay in touching it would have cost far more than $278.90. And time: the longer the expensive debt stands, the longer it charges. Compress any of the three — similar rates, similar balances, a bigger budget that kills everything quickly — and the gap shrinks towards a rounding error, which is why “it depends” is the correct answer for small, similar debts.

Adding $150 a month shrinks the gap between the methods — because it shrinks the time every balance spends under fire.

Notice what the second row teaches: adding money narrows the argument. At $850 a month the avalanche finishes a month sooner and the gap falls to $221.56. When a household finds extra money, the method debate matters less, not more — a useful thing to know before spending a weekend on it.

The behavioural half of the argument

There is a real case for the snowball, and it is not innumeracy — it is attrition. A payoff plan on the test set runs for nearly three years. Across three years there will be a bad month: a car repair, a cut shift, a bill nobody budgeted. Plans die in bad months, and a plan that has already banked a visible win — a whole debt crossed out in month 7 — is measurably easier to restart than one whose first milestone is scheduled for month 17. The avalanche is the cheaper plan if it is finished. The snowball is the plan more likely to be finished by someone who needs the wins. The honest verdict, printed next to every run of the calculator, is that the best plan is the one that survives contact with a bad month — and a hybrid is allowed: clear one tiny debt for the momentum, then switch to strict avalanche order for the rest.

Running the method off the calculator

Plenty of people execute a chosen order away from any website, and the tail of searches in this area shows it: free debt snowball spreadsheet templates, a snowball debt spreadsheet kept by hand, a debt avalanche spreadsheet for the other camp, a debt snowball app on the phone. All of these are the same instrument wearing different clothes — a table of balances with a target order — and a free snowball setup costs nothing but the discipline to update it. Two warnings travel with all of them. First, the spreadsheet must recompute the cascade: the month a debt dies, its payment jumps to the next target, and a sheet that forgets this flatters the finish date. Second, it must recompute shrinking minimums monthly, or its projections drift. A snowball method calculator does both automatically — and so does the free debt snowball calculator at the top of the hub page, which, like every debt snowball calculator free of charge on this site, prints the month each debt dies rather than just a finish date. That is why the practical pattern is to compute the plan in a calculator (any avalanche debt calculator or snowball tool that shows its months), then track the execution wherever you will actually look at it: sheet, app or notebook. The method is the order. The medium is whatever keeps you honest.