A debt snowball calculator builds a month-by-month plan that pays every minimum, then puts all extra money on your smallest debt until it is gone. Formula: Each month: pay every minimum, then send the extra plus any freed-up minimums to the target debt (smallest balance for snowball, highest APR for avalanche). Four debts totaling $18,500 with $540 of minimums and $200 extra are paid off in 31 months with $3,920.25 of interest using the snowball, or 30 months and $3,533.50 with the avalanche.
On this page
How to use the debt snowball calculator
- Type one debt per line: name, balance, APR, minimum payment. For example: Store card, 1800, 29.9, 55.
- Enter the extra amount you can pay each month on top of all minimums.
- Choose snowball (smallest balance first) or avalanche (highest APR first).
The debt snowball calculator shows months to pay everything off, total interest, and the order the debts are cleared. You can download the order as a spreadsheet.
How the debt snowball calculator works
Every month the tool adds interest to each debt at its APR divided by 12 and pays each minimum. Whatever is left of your monthly budget, which is all minimums plus the extra, goes to the target debt. When a debt is paid off, its minimum is not dropped from the budget; it rolls into the next target. That rolling payment is the snowball. The CFPB describes this exact process: after one debt is paid, dedicate that freed-up money to the next smallest debt.
Debt snowball calculator worked example
Four debts: Card A $6,500 at 24.9% (minimum $160), Car $9,000 at 6.9% ($275), Medical $1,200 at 0% ($50) and Store card $1,800 at 29.9% ($55), with $200 extra a month. Results from the debt snowball calculator:
| Method | Months | Interest | Payoff order |
|---|---|---|---|
| Snowball | 31 | $3,920.25 | Medical, Store card, Card A, Car |
| Avalanche | 30 | $3,533.50 | Store card, Medical, Card A, Car |
The avalanche saves $386.75 and one month here because it attacks the 29.9% and 24.9% cards first. The snowball clears the first debt sooner, which some people find keeps them going.
Snowball or avalanche: which should you pick?
The CFPB’s debt action plan says neither strategy is better than the other in every case; each has pluses and minuses. Paying the smallest debt first can show progress fast if you have many small debts, but you may pay more in total. Paying the highest rate first saves money overall, but it can feel slow when that debt is large. Run both in the debt snowball calculator. If the difference in interest is small, pick the one you are more likely to stick with.
Tips that make any plan work
Stop adding to the balances you are paying off, or the plan will never end. Set the extra payment as an automatic transfer. Recheck your list every few months, because rates on cards can change. If you have a windfall such as a tax refund, put it on the current target debt and rerun the tool. If the plan stretches for many years, compare it with a lower-rate consolidation loan using our debt consolidation calculator.
Common mistakes to avoid
A common mistake is entering a minimum payment that is lower than the monthly interest. The balance then never falls, and the plan can run for decades. If the debt snowball calculator says it cannot finish in 50 years, check each minimum against balance × APR ÷ 12. Another is forgetting debts such as medical bills, family loans or buy now, pay later plans. Put every debt on the list, even small ones, because the small ones are often the first wins.
Also leave room in your budget for emergencies. A small cash cushion stops one surprise bill from going back on a credit card and undoing months of progress.
Estimates for education only, not tax, legal or financial advice. Check current rules with the tax authority or a qualified adviser.
Related converters and calculators
Related calculators:
- Debt payoff calculator: one debt payoff
- Credit card payoff calculator: card payoff time
- Debt consolidation calculator: combine into one loan
Sources
CFPB: How to reduce your debt; CFPB Your Money, Your Goals: Debt action plan tool.
Formula and method
Each month: pay every minimum, then send the extra plus any freed-up minimums to the target debt (smallest balance for snowball, highest APR for avalanche)
Each result is computed from the inputs with the formula below, then rounded for display.
Questions about this calculator
What is the debt snowball method?
Pay minimums on everything, put extra money on the smallest balance, and roll each paid-off payment into the next smallest debt.
What is the avalanche method?
The same process, but you target the debt with the highest interest rate first.
Which saves more money?
The avalanche usually saves more interest. The snowball can clear individual debts sooner.
Do freed-up minimums roll over?
Yes. The tool keeps your total monthly budget the same, so each paid-off minimum goes to the next target.
What format do I use for my debts?
One per line: name, balance, APR, minimum payment, separated by commas.
Check the assumptions and units before relying on a result. Financial, tax and health estimates do not replace advice for your individual circumstances.
Report a calculation issue