How Know Your Date works
Updated November 2026
What a debt-free date is
A debt-free date is the month your last debt balance reaches zero, worked out from the debts you actually have: each balance, its APR, the minimum you pay on it, and any extra you can add. It turns "someday" into a month you can circle on a calendar, and it moves the moment your numbers do.
How the math works, month by month
Each month runs the same three steps. First, interest is added: your balance times your APR, divided by 12, rounded to the nearest cent. Next, your minimums are paid, on every debt, so nothing falls behind. Then your extra goes to work: every leftover dollar is aimed at the debt with the highest APR, because that debt charges you the most each month. When a debt is gone, the minimum you were paying on it does not leave your budget; it rolls into the extra aimed at the next highest APR.
That aim-highest-first order is called the avalanche method. It is the order that costs the least interest, because it kills the most expensive debt first. The other common order, snowball, clears the smallest balance first for the quick win; it feels good and usually costs more. This calculator runs the avalanche, and says so.
A worked example
Take the two debts this calculator opens with. A credit card: $1,000 at 24%, minimum $50. A personal loan: $500 at 12%, minimum $25. Pay minimums only and you need 25 months, and you hand over $348.72 in interest on $1,500 of debt. Now add $100 a month, aimed at the card first: you are done in 10 months, with $121.15 of interest. Starting in November 2026, your debt-free date is August 2027. The extra $100 saves 15 months and $227.57. Change the start month above and the same 10 months lands on a different month of the calendar; the count is the math, the month is the calendar.
How to read your result
Your date is the headline: the month the last balance hits zero under your plan. Months saved and interest saved compare your plan against paying minimums only, so you can see exactly what your extra buys. Your first move names the debt your extra aims at first. The table shows when each debt dies and what it cost you in interest along the way. If a warning appears, one of your minimums does not cover a month of interest on its debt, so that balance is growing; the date cannot arrive until that is fixed.
What the math takes as given
Your APRs stay fixed. You add no new charges to these debts. Your minimums stay at the amounts you typed, even as balances fall; many real card minimums shrink as the balance falls, which stretches a debt out, so a fixed minimum is the faster, more honest plan. If any of these change in real life, type the new numbers and read your new date.
What this calculator does not do
It runs one plan, the avalanche, for the debts you list. It does not compare payoff orders side by side, aim a one-time windfall, or print a month-by-month plan you can follow on paper. The Debt Payoff Calculator workbook does all three, on the same math. And none of this is financial advice: the result is only as good as the numbers you type in.
Sources
- The math on this page is the free Know Your Date sheet's math. When the sheet shipped, its numbers were checked three ways: the sheet itself, an independent spreadsheet recalculation, and a from-scratch recomputation. All three matched to the cent, including the worked example above.
Educational information only, not financial advice. Consider a qualified professional for decisions about your specific situation.