Debt Payoff Calculator
Enter each debt below, pick a payoff method, and see your month-by-month payoff plan.
Estimates only. Interest is calculated monthly at APR / 12. Minimum payments are assumed fixed each month.
What Is a Debt Payoff Calculator?
A debt payoff calculator is a free online tool that shows how long it takes to become debt-free and how much interest you will pay. You enter each balance, APR, and minimum payment, add any extra monthly payment, and choose the avalanche or snowball method. It then builds a month-by-month payoff plan with your debt-free date.
Use the calculator at the top of this page to run your own numbers. The guide below explains how the math works, compares the two payoff methods with verified examples, and answers common questions.
How to Use the Debt Payoff Calculator
- Add each debt. Type the name (optional), current balance, APR, and minimum monthly payment for every debt you want to include. You can add up to five debts.
- Enter your extra payment. This is any amount you can pay above your minimums each month, such as $100 or $300. Even a small extra payment can cut years off your payoff.
- Pick a payoff method. Choose avalanche to attack the highest APR first and pay the least interest, or snowball to clear the smallest balance first for faster early wins.
- Click calculate. The tool shows your payoff order, months to debt-free, debt-free month and year, total interest paid, and total amount paid.
- Compare methods. Switch between avalanche and snowball and recalculate. The difference in interest and months tells you the real cost of each strategy.
How the Payoff Math Works
Each month, interest is added to every open balance using the formula:
Monthly interest = balance x (APR / 100 / 12)
For a $5,200 balance at 24.99% APR, one month of interest is $5,200 x 0.020825 = $108.29. Your minimum payments go toward each debt first, then your extra payment targets the priority debt. When a debt is cleared, its freed-up payment rolls into the next debt, which is why both methods speed up over time.
If a payment does not cover one month of interest, the balance can never shrink, so the calculator flags it and asks you to raise the payment instead of producing a misleading plan.
Avalanche vs Snowball: Verified Example
Here is a realistic three-debt scenario run through the calculator above: a $5,200 travel rewards card at 24.99% APR ($130 minimum), a $2,800 retail store card at 19.99% APR ($70 minimum), and a $1,200 personal line of credit at 12.99% APR ($40 minimum), with a $300 extra payment each month. Total starting debt: $9,200.
| Avalanche (highest APR first) | Snowball (lowest balance first) | |
|---|---|---|
| Payoff order | Travel rewards card, retail store card, line of credit | Line of credit, retail store card, travel rewards card |
| Months to debt-free | 23 | 25 |
| Total interest paid | $1,849.65 | $2,359.46 |
| Total amount paid | $11,049.65 | $11,559.46 |
| Debt-free date | September 2028 | November 2028 |
In this scenario, avalanche clears the travel rewards card in month 15, the store card in month 22, and the line of credit in month 23. Snowball clears the line of credit in month 4, the store card in month 12, and the travel card in month 25. Avalanche saves $509.81 in interest and finishes two months earlier, while snowball delivers the first debt cleared 11 months sooner.
Which Method Should You Choose?
- Choose avalanche if your goal is to pay the least interest and finish fastest. It is the mathematically optimal strategy.
- Choose snowball if you have struggled to stay motivated. Clearing a small debt early gives a quick win that keeps many people on track.
- Either beats minimums alone. The $300 extra payment in the example is what does most of the work. Without it, the same three debts would take far longer and cost far more interest.
Frequently Asked Questions
Is the debt avalanche or snowball method better?
Avalanche is better mathematically: it always minimizes total interest and payoff time. Snowball can be better behaviorally because clearing a small debt early builds momentum. Run both in the calculator above and compare the dollar difference for your debts.
How is credit card interest calculated monthly?
Most US credit cards charge interest monthly at APR divided by 12. At 24.99% APR, the monthly rate is 2.0825%, so a $5,200 balance accrues about $108.29 in interest in one month before any payment is applied.
What extra payment should I make?
Pay as much extra as your budget allows, even $50 helps. In the example above, $300 extra per month cut total interest to $1,849.65 under avalanche. Without any extra payment, interest would have been several thousand dollars higher.
Can this calculator handle a 0% APR balance transfer card?
Yes. Enter 0 as the APR and the calculator charges no interest on that balance, clearing it in balance divided by payment months. Just remember that most 0% offers charge a 3 to 5% transfer fee up front.
What if my minimum payment does not cover the interest?
The calculator will warn you before simulating. A payment below the monthly interest means the balance grows every month, so you need to raise the payment, negotiate the rate, or consolidate to make progress.
Does the debt-free date include weekends or holidays?
The debt-free date is shown as a month and year, counting calendar months from today. It assumes you make every payment on time and do not add new debt during the payoff period.
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