Snowball or avalanche — what does the order actually save?
Enter every balance once. See both payoff orders run side by side, and the actual size of the gap between them.
First debt
Second debt
On top of every minimum above. This is the amount that actually moves between strategies.
More options(3)
Third debt (set a balance to include it)
$11,000 across 2 debts, paying $420 a month combined
$739
On the arithmetic alone, avalanche (highest rate first) is never more expensive than snowball (smallest balance first) — here it saves $739 in total interest by the time both are fully paid off. Snowball's whole case is the other number: it clears first debt in 1 year 2 months, against 2 years 10 months for whichever debt avalanche happens to attack first — an earlier win, for a price that on these numbers is $739.
- Avalanche total interest
- $3,513
- Snowball total interest
- $4,252
- Time to clear everything
- 3 years 1 month
Both lines spend the same money every month. Avalanche points every spare unit at the debt charging the most, so on balance it should sit at or below snowball's line the whole way through — the gap between them is interest avalanche avoided by paying it down sooner.
The order each method actually follows
Fixed at the start, from your numbers above
Avalanche — by rate, highest first
- 1. Second debt
- 2. First debt
Snowball — by balance, smallest first
- 1. First debt
- 2. Second debt
Why the gap is usually smaller than expected
Every debt gets its minimum every month under both methods — the only thing that moves is where the $150 on top gets pointed, and that only pulls ahead once a debt actually clears and frees its minimum to roll forward. With 2 debts here, that rollover happens at most 1 time before everything is paid off, which caps how far the two totals can drift apart. The gap grows with more debts, a bigger rate spread between them, and a smaller extra payment relative to the balances.
Two orders, the same money
Both methods assume you keep paying every debt's minimum, and both assume you have one extra amount left over each month once the minimums are covered. Neither is about paying more overall — they only disagree about which single debt that extra amount attacks first, and which debt inherits it once the first one is gone.
Avalanche points the extra at whichever debt charges the highest rate. Snowball points it at whichever balance is smallest, regardless of rate. Once that debt clears, its minimum payment doesn't disappear — it joins the extra and rolls onto the next debt in the same order, which is the mechanism the single-debt payoff calculator doesn't need to model, because there's only ever one debt to roll onto.
Why avalanche is never more expensive
Interest is charged on the balance still outstanding, at that debt's own rate — the same mechanism explained here for growth, running against you instead of for you. Sending the extra payment to the highest rate first means every pound of it stops accruing the largest possible charge as early as it can. Sending it anywhere else leaves a more expensive balance to keep compounding for longer than it strictly had to. That is the entire arithmetic case for avalanche, and it holds regardless of how many debts are involved or how large the balances are.
Why people still pick snowball
The number avalanche doesn't report is when does something actually disappear. Snowball is built to answer that: it targets the smallest balance specifically so the first debt closes as fast as possible, which is a completion rate question, not an interest question. The method's whole premise is that an early, visible win — a debt gone completely, not just smaller — is easier to keep paying toward than a plan whose first result is only a lower interest bill. This site takes no position on whether that premise holds for any particular reader; what it can do is price exactly what the earlier win costs in interest, on your own numbers, so the trade-off is a figure rather than a guess.
What this deliberately leaves out
- A recommendation. Whether the interest gap here is worth trading for an earlier first win depends on how likely you are to actually keep paying either plan — a question about temperament, not arithmetic, and this site does not tell you which to pick.
- New debts and balance changes. Every balance here only ever falls under its own minimum plus whatever extra reaches it — no further spending is modelled.
- Balance transfers, promotional rates and fees. Use the rate you actually expect to pay for the whole payoff, not an introductory one that will later reset.
- A hybrid order. Some people rank by a mix of balance and rate, or manually reorder partway through. This tool prices the two named methods as usually defined, run start to finish.
Common questions
Is avalanche always cheaper than snowball?
Why would anyone choose snowball if it costs more?
What happens once a debt is fully paid off?
Should I pay down debt or invest instead?
Not advice. This tool applies arithmetic to assumptions you entered. It does not know your circumstances, your tax position or your goals, and it is not a recommendation to buy, sell or hold anything. Past returns do not predict future ones, and no figure here is a forecast.