The debt snowball method: a full worked example
The snowball method pays the smallest balance first, then rolls each finished payment into the next debt. Here it is with real numbers, end to end — $14,200 of debt, $765 of monthly extra, and a finish line 14 months out.
The setup
Three debts, plus $765 per month available above all minimums (for this example we assume minimums of $45, $135 and $240):
| # | Debt | Balance | APR | Type | Cleared | Interest (plan) |
|---|---|---|---|---|---|---|
| 1 | Store card | $1,340 | 28.49% | Unsecured | Month 2 | $83 |
| 2 | Visa card | $4,820 | 24.99% | Unsecured | Month 8 | $412 |
| 3 | Car loan | $8,040 | 7.20% | Secured | Month 14 | $533 |
| Total | $14,200 | 14 months | $1,028 |
Worked example for illustration — your planner calculates from your own numbers, so your months and interest will differ.
Same debts, same income. The difference is entirely sequence and extra dollars.
The rollover mechanics
The snowball's engine is the rollover. Your total monthly outlay never changes — $1,185 here (all minimums plus $765 extra) — but as each debt dies, its minimum joins the attack:
- Months 1–2: the store card gets its $45 minimum plus all $765 extra = $810/month. It's gone by month 2.
- Months 3–8: the store card's $45 rolls over. The Visa now gets $135 + $45 + $765 = $945/month and is cleared by month 8.
- Months 9–14: the Visa's $135 rolls over too. The car loan gets everything — $1,185/month — and the plan ends at month 14.
Notice the acceleration: the last debt gets attacked by the combined minimums of every debt that came before it. That's why the chart drops faster at the end.
Why small wins work: the 2016 JCR study
In 2016, researchers David Gal and Blakeley McShane published a study in the Journal of Consumer Research on how repayment focus affects outcomes. They found that consumers who concentrated repayment on their smallest balances first — closing accounts sooner — reported stronger feelings of progress and were more likely to keep going and complete repayment than those who spread payments evenly across debts.
The mechanism is psychological, not mathematical: a closed account reads as a win, and wins sustain effort. One study isn't a law, and your arithmetic is your own — but it explains why snowball keeps being recommended despite avalanche's interest edge.
When avalanche wins instead
Avalanche (highest APR first) pays less interest whenever the expensive debt isn't also the smallest one. Choose avalanche when:
- Your highest-APR debt is large and years away from being cleared by snowball order.
- The APR spread is wide (e.g., a 28% card sitting behind a 24% card — every month of delay is expensive).
- You're confident you'll stay motivated without quick closures.
One honest detail about this worked example: the smallest balance (the 28.49% store card) is also the most expensive one, so snowball and avalanche start identically here. That's often true — and when it isn't, the planner shows both dates side by side so you can pick with your eyes open. Either way, the planner's engine does the rollovers for you.
Run your own snowball vs avalanche comparison — free.
Get the plannerSnowball FAQs
Snowball or avalanche — which saves more money?
Avalanche usually saves more interest because it attacks the highest APR first. Snowball often wins on follow-through because it closes accounts sooner. When the smallest balance also carries the highest APR — as in the example above — both methods start identically.
What should I do with a 0% promo debt in a snowball?
Use the 0% override: keep paying its minimum while the promo runs, but schedule it to be cleared before the promo end month, when the rate typically jumps. The planner flags it automatically.
Can I switch from snowball to avalanche mid-plan?
Yes. The planner recalculates the remaining payoff order and your debt-free date the moment you change the method. Nothing you've already paid is wasted.