Debt payoff calculator

How to use it

Add each debt with its balance, its yearly rate and the minimum the lender asks for. Choose how the extra is spent: Avalanche puts it on the highest rate, Snowball on the smallest balance, Your order where you list it (move debts with Up and Down). Then set the extra you can add each month. The result is the month you are debt-free, the order your debts clear in and the interest, with every other method and the minimums alone beside it.

Three debts, three orders

The example in the calculator: a store card of $900 at 12% with a $35 minimum, a credit card of $2,140 at 21.9% with $65, and a car loan of $7,900 at 6.4% with $190, plus $150 a month on top. Every method pays all three minimums each month; they differ only in where the $150 goes, and later, where each freed minimum goes.

The $150 is worth more than any choice of method: against the minimums alone it saves 1 year 6 months and $1,193.01. Between the methods the gap is smaller, and here avalanche and snowball finish in the same month; the car loan first costs the most, because it sends the extra to the lowest rate.

Why the extra grows

When a debt is paid off, its minimum does not go back into your pocket: it joins the extra and goes to the next debt. On the avalanche plan above, once the credit card is gone in month 12, its $65 joins the $150, and when the store card goes, its $35 follows. The monthly total stays at $440 to the end, so each debt falls faster than the one before. That rollover is the whole engine of a payoff plan, and it is why a plan finishes much sooner than the debts' own schedules suggest.

Debts in more than one currency

A student loan in euros and a credit card in dollars are paid from the same income, so they belong in one plan. Give each debt its currency and the rate you want to plan at; the calculator converts balances and minimums into one currency first, then plans them together. Your extra then goes where it saves the most, whichever currency the debt is in. The Tavala app plans the same way, converting at today's rate, and names any debt it cannot convert rather than guessing.

What it assumes

One rate per debt for the whole plan, interest of a twelfth of the yearly rate each month rounded to the cent, every payment made on time at the end of the month, and no new borrowing. Promotional rates, fees and lump sums are left out here; the payoff planner in the Tavala app takes dated rate changes and one-off payments. The figures are arithmetic, not advice about what to pay.