What a payoff plan is
A payoff plan is a schedule. It answers three questions: how much goes to each debt every month, which debt gets any money beyond the minimums, and what happens to a payment once its debt is gone.
Without a plan, each balance moves on its own track. With one, the debts work as a group. When one is paid off, its minimum payment does not disappear. It moves to the next debt in line, so the amount aimed at the remaining balances grows over time.
The calculator runs that schedule month by month until every balance reaches zero. The result is an estimate, not a promise, because real life brings new charges, rate changes and uneven payments that no model can see in advance.
The inputs that move the numbers
- Balance. What is owed today on each debt. Larger balances take longer to clear and give interest more room to build.
- APR. The yearly interest rate. The calculator divides it by 12 and charges that slice of the balance each month. A $1,000 balance at 24% APR picks up about $20 of interest in a month.
- Minimum payment. The required amount for each debt. If a minimum is smaller than one month of interest, the balance would never shrink, so the calculator raises it to that month's interest plus $1 and flags the change.
- Monthly extra. Anything paid beyond all the minimums combined. This input often changes the result more than any other, and the extra payment calculator compares several amounts side by side.
A debt on a 0% promotional rate can also carry an end month and the rate it switches to afterward. The calculator keeps it at 0% until that month, then applies the new rate.
Reading the three result columns
The results run the same debts and the same monthly total three ways. The only thing that changes between columns is which debt receives the extra money first.
- Snowball sends the extra to the smallest balance first.
- Avalanche sends it to the debt with the highest interest rate first.
- Your order follows the sequence you set, which can reflect things the math does not know about, such as a debt owed to family or a payment that feels heavier than the rest.
Each column lists a debt-free month, the number of months to get there, total interest and total paid. When the columns land close together, the order matters little for those particular debts. When they spread apart, the gap shows what the ordering choice is worth in dollars and months. The snowball vs avalanche calculator looks at that gap in more detail.
What the balance chart adds
The chart plots the total remaining balance month by month. Early on the line often falls slowly, because a bigger share of each payment goes to interest while balances are high.
As debts are cleared and their minimums roll forward, the line tends to bend downward faster. Those bends usually line up with the payoff month of each debt in the order list. A long, gentle slope near the start is common. It reflects how interest behaves on larger balances rather than a plan that is stalling.
Why real statements can differ
The calculator uses a monthly model: interest is charged once a month at APR divided by 12, then payments are applied. Many card issuers commonly figure interest daily on an average balance, so actual charges can be off by a few dollars a month.
The estimate also assumes no new charges, steady rates and the same payment every month. When any of those change, running the numbers again gives an updated picture. For a closer look at the finish line and each debt's individual payoff month, the debt-free date calculator puts the date front and center.