Transparent method
The formula
Worked example
Example inputs
How to interpret the result
Directing every extra dollar at the highest-rate balance first minimizes total interest paid across all the debts combined, mathematically, even though it can mean a smaller balance sits untouched and doesn't get the satisfaction of an early payoff. The trade is real total-dollar savings against the motivational benefit smallest-balance-first offers instead.
Before you rely on it
What to check
Confirm every other balance's minimum payment stays current while directing extra cash at the single highest-rate debt, since missing a minimum elsewhere undermines the strategy's whole benefit.
The common error
Where people go wrong with debt avalanche calculator
Splitting extra payment across multiple balances instead of concentrating it entirely on the highest-rate debt. Diluting the extra payment reduces the total interest savings the avalanche method is specifically built to capture.
Sensitivity evidence
How debt a balance changes the avalanche interest savings vs. snowball
| Debt A balance | Avalanche interest savings vs. snowball | Avalanche payoff time | Snowball payoff time |
|---|---|---|---|
| $6,400 | $531 | 30.0 months | 31.0 months |
| $7,200 | $616 | 32.0 months | 32.0 months |
| $8,000worked example | $701 | 33.0 months | 34.0 months |
| $8,800 | $787 | 34.0 months | 35.0 months |
| $9,600 | $873 | 36.0 months | 37.0 months |
Every input, tested
Which input moves the avalanche interest savings vs. snowball most
| Input | Tested from | To | Avalanche interest savings vs. snowball at each end | Swing |
|---|---|---|---|---|
| Debt A APR | 22.0% | 26.0% | $563 to $853 | $290 (41%) |
| Debt B balance | $4,500 | $5,500 | $601 to $801 | $200 (29%) |
| Debt B APR | 10.0% | 14.0% | $791 to $604 | $187 (27%) |
| Debt A balance | $7,200 | $8,800 | $616 to $787 | $171 (24%) |
| Debt B minimum payment | $135 | $165 | $754 to $652 | $102 (15%) |
| Debt A minimum payment | $180 | $220 | $741 to $663 | $79 (11%) |
| Extra monthly payoff budget | $270 | $330 | $729 to $675 | $54 (7.8%) |
| Debt C balance | $10,800 | $13,200 | $694 to $708 | $13 (1.9%) |
| Debt C APR | 6.0% | 8.0% | $695 to $707 | $12 (1.7%) |
| Debt C minimum payment | $225 | $275 | $705 to $697 | $8.26 (1.2%) |
Two variables at once
Avalanche interest savings vs. snowball by debt a balance and debt a APR
| Debt A balance \ Debt A APR | 20.0% | 24.0% | 28.0% |
|---|---|---|---|
| $6,400 | $333 | $531 | $757 |
| $7,200 | $383 | $616 | $884 |
| $8,000 | $433 | $701 | $1,015 |
| $8,800 | $482 | $787 | $1,151 |
| $9,600 | $531 | $873 | $3,586 |
Step by step
The worked example, input by input
| Input | Value used |
|---|---|
| Debt A balance | $8,000 |
| Debt A APR | 24.0% |
| Debt A minimum payment | $200 |
| Debt B balance | $5,000 |
| Debt B APR | 12.0% |
| Debt B minimum payment | $150 |
| Debt C balance | $12,000 |
| Debt C APR | 7.0% |
| Debt C minimum payment | $250 |
| Extra monthly payoff budget | $300 |
| Avalanche interest savings vs. snowball | $701 |
| Avalanche payoff time | 33.0 months |
| Snowball payoff time | 34.0 months |
Where the inputs come from
List each debt with its balance, APR and required minimum payment from your statements, and enter the extra amount you can pay each month. The avalanche order sorts debts by interest rate, highest first, regardless of balance. Use the actual rates, including any penalty APR that has been triggered, and remember that a promotional 0% balance is lowest priority until the promotion ends. Recheck the order if a rate changes.
Using the avalanche interest savings vs. snowball in a real decision
Expect the early months to feel slow if the highest-rate debt is also the largest.
When the result stops applying
The method assumes fixed rates and steady extra payments. It does not consider psychological progress, credit score effects or the value of eliminating a small account with an annual fee. Low-rate debt with a tax deduction, such as some student loans, may deserve a different priority. New charges on paid-off cards undo the progress.
What to compare it with
Compare with the smallest-balance-first order on the debt snowball calculator, and see both side by side on the snowball versus avalanche page. The credit card payoff and balance transfer calculators show the effect of lowering a rate. The emergency fund calculator explains why a small cash cushion protects the plan.
People also ask
Frequently asked questions
How does the debt avalanche work?
Pay the minimum on every debt and put all extra money on the debt with the highest interest rate, then move to the next highest as each is cleared.
Does the avalanche always save the most interest?
Yes, for fixed rates and a fixed total payment. No other ordering of the payments can cost less interest.
What if my highest-rate debt is a tiny balance?
Then the avalanche also clears it quickly, giving an early win. The order only feels slow when the top-rate balance is large.