Avalanche vs. Snowball Debt Payoff
Your debts
List at least two — balance and APR are on each statement. We compare both payoff strategies with your actual numbers.
0% promo? Enter it — we don't model the rate jumping later, so rerun when it changes
It's on your statement — leave blank and we'll estimate 2% of the balance ($25 minimum)
0% promo? Enter it — we don't model the rate jumping later, so rerun when it changes
It's on your statement — leave blank and we'll estimate 2% of the balance ($25 minimum)
$0 is fine — freed-up minimums still roll over as debts clear, so the strategies can still differ
How we calculate this
Both strategies run through the same month-by-month simulation. Your total monthly budget is every minimum payment plus your extra amount, paid in full every month until you're debt-free. Interest compounds monthly at each debt's APR divided by 12. Whatever's left after minimums goes to the target debt — and when a debt is cleared, its minimum payment stays in the pool and rolls into the next target. That rollover is why payoff accelerates near the end under either strategy.
Avalanche sends the extra money to the highest-APR debt. Snowball sends it to the smallest current balance. That's the entire difference.
Here's the honest math: avalanche always wins or ties on interest. With a fixed monthly budget, paying down the most expensive dollar of debt first is provably optimal — there is no combination of balances and rates where snowball pays less interest. If a tool tells you otherwise, it's calculating something wrong.
So why does snowball exist? Because the math only matters if you keep going. Behavioral research — including a well-known Kellogg School analysis of thousands of real borrowers — found that people who concentrate payments on their smallest balance first are more likely to stick with repayment and actually eliminate their debt. A quick early win is fuel. The most expensive strategy isn't snowball or avalanche — it's the one you abandon in month six. That's why we show you the exact dollar price of the motivational head start and let you decide.
What we don't model: promo-rate expirations (a 0% rate that jumps to 24% next spring can flip the avalanche order — rerun when a rate changes), new charges on the cards, and variable-APR drift.
Real scenarios
Three cards, $14,500 total: the trade-off is real
Cards of $6,500 at 26%, $4,200 at 18%, and $3,800 at 22%, with $200 extra per month. Avalanche pays $6,407 in interest and finishes in 43 months; snowball pays $7,385 and takes 45. Avalanche saves $978 — but snowball clears its first card in month 17 versus month 26, nine months of visible progress sooner.
Sometimes there is no dilemma
A $2,000 store card at 27%, a $6,000 credit card at 19%, and a $9,000 car loan at 7%, with $150 extra: the smallest debt is also the most expensive one, so both strategies target it first and produce the identical plan — $3,394 in interest, debt-free in 36 months. When your balances line up this way, just start.
The price of motivation, exactly
A $12,000 car loan at 6% next to a $900 store card at 0% promo, with $100 extra. Avalanche ignores the 0% card until month 36; snowball wipes it out by month 8 — twenty-eight months of head start on the first win. The cost of taking it: $72.53 in extra interest, and both plans finish the same month. That's a cheap price for momentum if you need it.