What This Tool Does
Use the calculator to plan a single balance or compare payoff orders for multiple debts. It uses your balances, APRs, minimum payments, fees, and extra-payment amounts to estimate payoff timing, interest, payment order, and month-by-month schedules.
Choose a Payoff Mode
Choose Multiple debts (avalanche vs snowball) to compare two payment orders. This mode requires at least two valid debts and supports up to 12. Choose Single card payoff for one balance and its payment details.
How to Use the Calculator
- Select Multiple debts (avalanche vs snowball) or Single card payoff.
- In multiple-debt mode, complete the starting three rows with each debt's name, balance, APR, minimum payment, and Monthly fee ($, optional). Click Add debt for another row, up to 12. Use the row's Remove debt control to delete an unwanted row.
- Enter Extra monthly payment budget ($, optional). This amount is added to all entered minimum payments.
- Use Schedule to display to choose which strategy gets the detailed schedule. The comparison statistics still calculate both strategies.
- In single-card mode, enter Current balance ($), Annual percentage rate, APR (%), Minimum payment per month ($), Extra payment per month ($, optional), and Monthly fee ($, optional).
- Click Calculate. After results appear, use Copy result or Download result (.txt) to save the generated text.
- Click Reset to clear the entries and restore the starting rows.
Unused multi-debt rows can remain completely blank and are skipped. A row with only some fields filled is not skipped; complete it or remove it.
Validation and Calculation Errors
Balance and minimum payment must be greater than 0. APR must be between 0 and 100. Optional monthly fees, Extra monthly payment budget ($, optional), and Extra payment per month ($, optional) must be 0 or greater. Multiple-debt mode also needs at least two valid debts.
For multiple debts, the total monthly budget must exceed the combined first month's interest. If recurring fees are large enough, they can still keep a simulation from paying off within the 100-year limit even when this initial check passes.
How Payoff Strategies Are Calculated
- Avalanche: orders debts by highest APR first.
- Snowball: orders debts by entered starting balance, smallest first. That order is fixed during the simulation; ties use the higher APR first.
For each month, interest uses the entered APR converted to a monthly rate: r = APR / 100 / 12. Fees are added to the balance before payments. Minimum payments are applied up to each debt's remaining balance, then the available extra budget is applied in the selected strategy order. The nominal budget is the sum of minimum payments plus the extra amount, but the actual payment can be lower when the remaining balance is smaller. When a debt is paid off, unused budget can continue to the next debt.
Understanding the Results
Multi-debt results show statistics for Avalanche and Snowball, including months to payoff, a calculated payoff date, total interest, and interest saved. They also show both payment-order tables and the strategy selected under Schedule to display. If only one strategy succeeds within 100 years, the other can show 100+ yrs while the successful strategy's schedule is displayed.
In that schedule, the Interest column is the interest for that month, not total interest. Total interest appears in the strategy statistics. The schedule also lists the payment, each debt's remaining balance, and total remaining balance.
Single-card results show the payoff statistics, the formula used, assumptions, and a full monthly schedule. The payoff date uses the browser's current date plus the simulated number of months. Use Copy result or Download result (.txt) after calculating.
Assumptions and Limitations
- APR is converted to a monthly rate, and entered recurring fees are added each month before payment.
- APR and minimum payments remain fixed in the simulation. Promotional rates, penalty APRs, issuer-specific minimum formulas, new charges, missed payments, and balance transfers are not modeled.
- The simulation is limited to 100 years. The multi-debt precheck compares the budget with combined first-month interest but does not include monthly fees, so recurring fees can still lead to the 100-year ceiling.
- The payoff date is an estimate based on the browser's current date and the simulated number of months.
- The calculator uses the figures you enter. It does not fetch live creditor data or account terms, contact creditors, negotiate settlements or rates, or model one-time payoff fees or early-payoff penalties.
This is a mathematical plan, not a creditor payoff quote, guaranteed outcome, or personalized financial advice. Actual results depend on creditor terms, rate changes, fees, and whether payments are made as planned.
Privacy Note
The calculator values are processed locally by the calculation script in your browser. The page also includes analytics and a subscription form; an email submitted through that form is sent to /assets/subscribe.php.
Frequently Asked Questions
What is the difference between debt avalanche and debt snowball?
Debt avalanche orders debts by highest APR first. Debt snowball orders them by entered starting balance, smallest first, and keeps that order during the simulation. Extra budget follows the selected order after minimum payments are applied up to each debt's remaining balance.
How does the extra payment roll over between debts?
The nominal monthly budget is the sum of the entered minimum payments plus the extra amount. Payments are capped at the remaining balance, so the actual payment can be lower in a payoff month. Any available budget can then continue to the next debt in the strategy order.
How are monthly fees handled?
Any monthly fee you enter for a debt is added to that debt's balance every month, alongside interest, before payments are applied. This models a recurring account fee - it is not a one-time payoff fee or an early-payoff penalty, which this calculator does not model.
Can I calculate a single credit card payoff instead of multiple debts?
Yes. Switch to Single card payoff, which uses one balance, APR, minimum payment, optional extra payment, and optional monthly fee to build a full month-by-month payoff schedule.
Does this tool negotiate my debt or guarantee a payoff outcome?
No. This is a mathematical planning tool only. It does not contact creditors, negotiate settlements or interest rates, fetch live account terms, or guarantee any real-world payoff outcome - actual results depend on your creditors' terms, any rate changes, fees, and whether payments are made as planned.