Debt Payoff Calculator: Snowball vs. Avalanche
This calculator takes every debt you have, the minimum on each, and whatever extra you can pay, then runs the payoff month by month under the two standard orders: snowball (smallest balance first) and avalanche (highest APR first). Avalanche always costs the least interest; snowball clears your first balance sooner. On typical mixes of cards and loans the gap between them is a few hundred dollars, not thousands.
It then checks whether a consolidation loan or an 18-month 0% balance transfer would beat either plan at the same monthly outlay, ranks all options by total cost, and shows a debt-free date for each. The example below is prefilled; replace it with your own numbers and the results update as you type. Nothing you enter leaves your browser.
Results
Compared with your current plan
Debt-free on the same date, $282 less interest
By switching to Debt avalanche. Your current plan finishes October 2028 with $2,412 in interest.
| Strategy | Debt-free | Months | Total interest | First debt gone (month) | Saved vs minimums |
|---|---|---|---|---|---|
| Minimums only | Jul 2031 | 58 | $4,999 | 25 | — |
| Snowball | Oct 2028 | 25 | $2,412 | 10 | $2,588 |
| Avalanche | Oct 2028 | 25 | $2,129 | 25 | $2,870 |
Avalanche saves you $282 versus snowball, but your first debt clears in 25 months instead of 10. If early wins keep you going, snowball costs $282 extra for that.
At minimum payments only, these debts take 4 years 10 months and cost $4,999 in interest. With $150 extra a month you are debt-free in 2 years 1 month after $2,412 in interest.
Enable JavaScript to edit the numbers above and see your own plan, charts, and month-by-month schedule.
Frequently asked questions
What is the difference between debt snowball and debt avalanche?
Both methods pay every minimum and send all extra money to one target debt at a time. Snowball targets the smallest balance first, so you get a debt to zero quickly and roll its minimum into the next one. Avalanche targets the highest APR first, which minimizes total interest. The monthly outlay is identical; only the order changes.
How much more does snowball cost than avalanche?
It depends on how far apart your rates are and whether your small balances happen to carry high rates. On the example above the difference is $282 over 25 months. When your smallest debt also has the highest rate, the two orders are identical and cost the same. Large low-rate loans mixed with small high-rate cards make the gap wider.
Does paying extra really make a big difference?
Yes, because early extra payments remove principal that would otherwise be charged interest every month for years. On two debts totaling $8,900 at these rates, $150 a month extra cuts the payoff from 58 months to 25 and saves roughly $2,600 in interest. The table under the calculator shows the effect of each additional $50, $100 or $250.
How does the calculator decide whether consolidation or a balance transfer is better?
It simulates each option with the same monthly outlay you already have. A consolidation loan is assumed at a rate matched to your self-reported credit range plus a 3% fee; a balance transfer is assumed at 3% fee, 0% for 18 months, then 24%. Both are ranked by total cost against your current plan, and every assumption is listed so you can compare with real quotes.
Is my data stored anywhere?
No. The math runs in your browser and nothing is sent to a server. Your last inputs are kept in this browser's local storage so they are still there when you come back, and the Clear my data button removes them. A share link encodes your numbers in the link itself; only people you send it to can see it.
What if my minimum payment is smaller than the monthly interest?
Then the balance grows instead of shrinking, and the calculator says so: the payoff date shows as never and the decision block flags the debt. Any extra amount, even $25 a month, changes the outcome, because it starts reducing principal. Calling the issuer about a hardship rate or a nonprofit debt management plan is the usual next step.