Debt Payoff Calculator

How are the minimum payments worked out?

The tool has no field for them, so each minimum is set at 1% of the starting balance plus one month of interest, with a floor of 25, and then held fixed. These are figures built into this tool, not your lender’s rules. On the starting debts the three minimums add up to $202.46 a month. Replace them mentally with your real minimums if they differ.

How does the extra payment flow between debts?

Each month the tool pays every open debt its minimum, then spends the rest of the budget (all minimums plus your extra amount) on the target debt. When a debt is cleared, its minimum stays in the budget and moves to the next target, and any leftover in that same month spills over too. That rolling is what makes the strategy work, and it is why the monthly budget line stays constant.

In what order does each strategy pay debts?

Avalanche targets the highest interest rate first and snowball targets the smallest current balance first. Ties go to the debt entered first. The “Payoff Order” line shows the order in which balances reached zero, which is not always the target order, because a small debt can be cleared by its own minimums.

What does “Interest Saved vs Min Only” compare against?

It compares against paying only the fixed minimums on each debt, with no extra and no rolling of cleared payments. Because the strategy run does roll payments, it can show savings even with an extra payment of 0. On the starting debts, an extra of 0 gives 58 months instead of 66 and $132.61 less interest.

How is interest calculated?

Each month, rate ÷ 12 is applied to every open balance first, and payments are taken after that. There is no daily compounding, no grace period and no change of rate during payoff. A debt with a 0% rate has its balance reduced only by payments, and a single $5,000 debt at 0% with a minimum of $50 takes 100 months.

What if a balance is 0, a field is blank, or nothing is entered?

Debts with a balance of 0 are skipped, and if all three are 0 the tool asks for at least one debt. A rate of 0% or an extra payment of 0 is used as entered. Clearing a box counts as 0, so an emptied rate means a 0% rate and an emptied extra payment means no extra, and negative numbers are treated as 0. If a plan would take more than 100 years, the result says so instead of showing a number.

What is not modelled?

New purchases, fees, penalty rates, variable or promotional rates, balance transfers, lump-sum payments, changing income, and any effect on a credit score. It also handles at most three debts. Real rates, fees and lender rules change, so the figures are a projection from your entries.

Does it say which strategy I should choose?

No. It reports both on the same inputs, and the results can be close or far apart. In the starting scenario avalanche takes 23 months and snowball 24. How much those differences matter to you, and which order you will stick with, is your decision.