Debt Snowball and Avalanche Planner

How to use the debt payoff planner

1. Under Your debts, enter each debt: a Name, the Balance, the Interest rate (APR, %) and the Minimum monthly payment from your statement. Use Add a debt for more rows (up to 20) and Remove to delete one.
2. Enter your Extra monthly payment: the amount you can pay on top of all the minimums each month. It can be 0.
3. Choose the Payoff order: Avalanche (highest rate first), Snowball (smallest balance first) or Custom (order of the list), which follows the order of your rows.
4. Choose the Currency.

The results show your Monthly budget (all minimums plus the extra), the Time to be debt-free, the month you are Debt-free by, the Total interest, the Total paid and the Interest saved vs minimums only. The Strategy comparison table puts the three orders and Minimum payments only side by side. The Payoff order and dates table shows when each debt is cleared and how much interest it costs. The chart follows the total balance month by month, and the Month-by-month plan can be exported with Download CSV, with one balance column per debt.

How the plan is calculated

The tool simulates your debts one month at a time, the way a spreadsheet would:

1. Interest is added to each open debt: balance × APR ÷ 12, rounded to the cent.
2. Every open debt receives its minimum payment (or its remaining balance if smaller).
3. The rest of the monthly budget goes to the first open debt in the payoff order, then the next.

The budget stays the same every month: sum of all the original minimums + extra. When a debt is paid off, its minimum “rolls over” to the next debt in line. That rollover is what makes both methods fast: the payment on the last debt grows like a snowball. The Minimum payments only line is the reference without the extra and without rollover: each debt is paid only its own minimum until it is cleared.

Snowball or avalanche?

• The avalanche method pays the highest interest rate first. It always costs the least interest (or ties), because every extra dollar cancels the most expensive debt.
• The snowball method pays the smallest balance first. It costs a little more, but the first debt disappears sooner, which keeps many people motivated.

Example with the default values ($5,000 credit card at 19.99%, $12,000 car loan at 7.9%, $3,000 line of credit at 9.5%, minimums of $150, $300 and $60, plus $200 extra, so $710 a month): both methods clear the $20,000 in 33 months. The avalanche costs $2,819.58 in interest and clears the card in month 17; the snowball costs $3,180.64 but clears the line of credit in month 13. With minimum payments only it would take 62 months and $5,145.14 of interest.

Limits

Rates and minimums are assumed fixed. Real credit cards charge daily interest and their minimum payment shrinks with the balance, so statements will differ a little. New purchases, fees and promotional rates are not included. The results are estimates, not financial advice.