Finance
Debt Payoff Calculator
Compare snowball and avalanche payoff plans for up to four debts, with fixed minimum payments and an extra monthly budget. Results estimate payoff duration and interest, not a calendar debt-free date.
Your details
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Your result
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Useful next checks
- Compare a few scenarios before making a decision.
- Check rates, fees, tax, and timing outside the estimate.
- Use the explanation below to understand the formula.
Intro
Use this debt payoff calculator to compare snowball and avalanche repayment strategies. Enter up to four debts with balances, APRs, and minimum payments, then add any extra monthly repayment budget.
What this debt payoff calculator does
The calculator estimates:
- Debt-free time.
- Total interest paid.
- Which debt to attack first.
- How avalanche compares with snowball.
- The order debts may be cleared.
How it works
The monthly budget is the sum of the entered fixed minimum payments plus the extra payment. That total remains available as debts are cleared; it is not reduced when a minimum payment is freed up.
Monthly budget = total starting minimum payments + extra payment
Interest on each debt = its opening balance × APR / 100 / 12
After adding interest, the planner pays fixed minimums to the other active debts and applies the rest of the budget to the current target. If that debt clears, unused money moves to the next target in the same month.
Avalanche ranks debts by highest APR, with the smaller balance breaking a tie. Snowball ranks them by smallest current balance, with the higher APR breaking a tie. The ranking is reconsidered as balances change.
Example calculation
The worked examples on this page use US dollars (USD). Choosing UK - GBP changes the calculator's currency labels; it does not convert your entries or these examples.
Enter these three debts, leave the fourth balance at $0, and set the extra monthly payment to $150:
| Debt | Starting balance | APR | Fixed minimum per month |
|---|---|---|---|
| Credit card | $3,000 | 24.9% | $90 |
| Personal loan | $1,000 | 7% | $40 |
| Store card | $2,000 | 29.9% | $50 |
Starting debt is $6,000. Minimums total $90 + $40 + $50 = $180, so the fixed monthly budget is $180 + $150 = $330. Assume no new borrowing, fees, missed payments or rate changes.
| Result | Avalanche | Snowball |
|---|---|---|
| First target | Store card: highest APR | Personal loan: smallest balance |
| Debt-free time | 23 months: 1 year, 11 months | 24 months: 2 years |
| Total interest | $1,413.24 | $1,665.64 |
| Total repaid | $7,413.24 | $7,665.64 |
| Clearance order and month | Store card 12; credit card 22; personal loan 23 | Personal loan 6; store card 15; credit card 24 |
In avalanche’s first month, the store card gains $2,000 × 0.299 / 12 = approximately $49.83 interest. The other debts receive $90 and $40, leaving $200 of the $330 budget for the store card. Its closing balance is approximately $1,849.83.
The final payment uses only what is needed to clear the remaining debt, so total repaid is not the full $330 multiplied by the number of months. The totals above use unrounded monthly interest; displayed per-debt figures may not add exactly because each is rounded separately.
How to use the result
Use the result to choose a repayment order and a monthly budget you can sustain. Try a few extra-payment amounts to compare how much repayment time you could save.
For a single card, use the Credit Card Payoff Calculator. For fixed loans, compare with the Loan Repayment Calculator.
Assumptions and limitations
- Up to four positive-balance debts are included. Each needs a non-negative APR and a positive fixed minimum; a zero balance is ignored.
- Payoff time is a duration in years and months, not a calendar debt-free date. Clearance months in the worked example count from the start of the scenario.
- Rates stay constant and are divided by 12. The model does not reproduce daily interest or exact payment dates.
- Minimums remain fixed in cash rather than falling as a percentage of the balance. The original total budget is reused until the final payment.
- There are no fees, payment holidays, promotional-rate changes or new borrowing. Early repayment restrictions and priority-debt consequences are not assessed.
- Interest and balances keep full precision during the calculation; the display rounds to cents.
- An input is rejected if a debt’s minimum plus the extra payment does not exceed its opening monthly interest. Plans that do not clear within 600 months are also rejected. Passing these checks does not establish that the budget is affordable.
- This is a planning estimate, not debt advice. For UK readers who cannot afford minimum payments or essential bills, MoneyHelper’s debt advice locator can help you find free advice.
Frequently asked questions
Does this calculate a calendar debt-free date?
No. It estimates repayment time in years and months. The calculator does not use a start date or calculate a calendar payoff date.
Which strategy saves the most interest?
Avalanche targets the highest APR first. In the worked example it has the lower interest total, under the stated fixed-budget assumptions; actual rates, fees and payment rules can change the comparison.
Why use snowball?
Snowball can be motivating because smaller debts disappear sooner.
What if I cannot afford the minimums?
Speak with your lenders or a qualified debt charity before relying on a payoff plan.
What is the avalanche method?
The avalanche method targets the highest APR debt first while keeping minimum payments going on the rest.
What is the snowball method?
The snowball method targets the smallest balance first, which may feel motivating but can cost more interest.
Can I add more than four debts?
No. This calculator supports up to four debts in one scenario. Each debt keeps its own balance, APR and fixed minimum payment.