How to use the debt snowball calculator
Prepare the values for this calculation
Model multi-debt payoff using lowest-balance-first snowball targeting. Use the formula below to check that it answers your question. Read the input units before transferring figures from a statement, measurement or dataset.
Enter and check each input
- Debts — name,balance,APR,min payment: keep one record per line and preserve the column order shown in the example. Replace the example data with your own complete dataset.
- Extra monthly payment: enter a value at least 0. Use the unit named in the label or selected above. Do not leave this required field blank.
- Method: choose Snowball. Match this selection to the data you enter.
The input table gives a complete example. Keep units and time periods consistent across related fields.
Calculate and resolve any input error
Choose Calculate after entering the values. Changes also update the answer after a short pause. If an error appears, follow its message, correct the field and calculate again. Reset restores the example values.
Interpret the answer
Check Modeled payoff time first. With the unchanged example inputs, it is 22 months. Compare the additional metrics with the primary result; each has its own label and unit.
Compare and keep a useful result
For a controlled comparison, keep every other example input unchanged and change Extra monthly payment from 200 to 220. The resulting Modeled payoff time is 21 months. This illustrates the equation’s response to that input, rather than a forecast of real events.
Read the chart’s axis labels and data table. A scenario curve changes one stated input while holding the others fixed; it does not add external observations. Use Download graph to save an available chart as a PNG.
Use Copy result or Download CSV to keep the answer. Share tool shares the page address without placing your input values in the URL. Recheck inputs and assumptions before using the result for a decision.
Debt Snowball Calculator formula
Each month interest accrues, minimums are paid, then extra payment targets the highest APR balance.
Inputs and units
| Input | Format / range | Example |
|---|---|---|
| Debts — name,balance,APR,min payment | One row per line | Card A,5000,24,150
Card B,3000,12,100 |
| Extra monthly payment | minimum 0 | 200 |
| Method | Select an option | Snowball |
Worked example
Using the example inputs above, the modeled payoff time is 22 months.
- Modeled payoff time
- 22 months
- Approx. years
- 1.83
- Total modeled interest
- $1,731.44
- Method
- snowball
Results and assumptions
The output uses the modeled payoff time convention and formula shown above. Match the entered units and source assumptions when comparing results.
Rates, fees and tax assumptions are entered values. This calculation does not quote a lender, determine a tax liability or guarantee an investment return.
Fix an input or unexpected result
Extra monthly payment is required. Enter extra monthly payment using the format and bounds in the input table. Zero and an empty field are different: use zero only if it is allowed and represents your data.
If your answer differs from the example, choose Reset and compare every field, including selected units and options. Check percentage versus decimal entry and whether values describe the same period. Round only the final displayed answer when reproducing the formula.
If a discrepancy remains, report the calculator issue with the page address, non-sensitive example inputs, actual result, expected result and a reference for your calculation.