The data, the math, and the assumptions behind every calculator.
Last updated: 2 November 2026.
Debt figures cited on this site come from two official US sources. The Federal Reserve Bank of New York Household Debt and Credit Report, published quarterly, covers total household balances and delinquency rates. The Federal Reserve G.19 statistical release, published monthly, covers consumer credit totals and average credit card interest rates. When we cite a figure, we name the release it came from. We do not use figures from marketing surveys, press releases, or other blogs as inputs.
Every payoff calculator on this site runs the same month by month simulation. Each simulated month has two steps. First, interest accrues: the annual APR divided by 12, applied to the current balance. Second, your payment is applied, interest first, then principal. There are no formula shortcuts. It is the same math a careful spreadsheet would do, repeated every month until every balance reaches zero.
The debt snowball orders your debts by balance, smallest first. You pay minimums on everything and throw every extra dollar at the smallest debt. When it is paid off, its entire payment rolls forward to the next smallest debt. The debt avalanche works the same way but orders by APR, highest first, which minimizes total interest. Both methods roll freed payments forward exactly as the real world methods do. That rolling is the whole engine of both strategies, and our calculators model it payment by payment.
Our minimum payment trap calculator uses the most common US card formula: the greater of 2 percent of the balance or $25, recalculated every month as the balance falls. This matches the disclosure formula behind the minimum payment warning box required on card statements under the CARD Act. Because the payment shrinks with the balance, the payoff stretches into decades. That shrinking payment is the trap, and the calculator shows it month by month.
Every simulation assumes no new charges during the payoff, no annual fees or late fees unless the page says otherwise, payments made on time every month, and constant APRs. Minimums are the greater of 2 percent or $25 unless stated. Results are rounded to the cent each month, the way real statements are. Change any assumption and the timeline changes, which is why the calculators let you adjust the inputs that matter most.
These are estimates, not financial advice. Real life includes fees, rate changes, missed payments, and new charges, all of which the simplified assumptions leave out. Actual outcomes will differ, sometimes materially. The calculators cannot see your full financial picture and they are not a substitute for a licensed financial advisor or a nonprofit credit counselor. Read the full disclaimer before acting on any result.