PayoffDebt is a small, independent project. It does two things: it compares the debt snowball and debt avalanche strategies side by side using your real numbers, and it publishes short, carefully-checked guides to the money math behind them. No accounts, no data collection, and nothing for sale.
How we keep the numbers honest
The math is not a black box. Every result is computed in your own browser from a formula we document in full in the methodology — you can read exactly how interest, minimum payments, promo-rate cliffs, and payoff order are handled. That payoff engine is covered by an automated test suite, including randomized “invariant” tests that check its results stay internally consistent across many generated debt scenarios. When we state a number, we can show our work.
We're also explicit about the limits. The calculator compounds interest monthly and assumes your rates and payments stay as entered; your card issuer's daily compounding will differ slightly. Each guide says where its assumptions end.
How we research the guides
Debt is a “your money” topic, so we hold the guides to a higher bar. They're written and reviewed against primary, non-commercial sources — chiefly the Consumer Financial Protection Bureau, the Federal Reserve, and the Federal Trade Commission — and every article lists the specific sources it draws on. Our full approach is written up in our editorial standards.
How this site is funded
The site is free — no accounts, no paywalls — and supported by advertising served through Google AdSense. Ads never have access to the financial figures you enter into the calculator; those stay in your browser (the Privacy page explains exactly what the ad network can and can't see, and how to opt out of personalized ads). We have no affiliate links and no paid sponsorships. If that ever changes, we'll disclose it clearly, right here.
Not financial advice
This is an educational tool, not a substitute for advice from a qualified financial professional. It shows you the arithmetic of well-known strategies; it doesn't know your full situation.
Found a mistake?
We want to know. If a number looks wrong or a guide reads unclearly, get in touch — we check every report against the methodology and fix what's broken. Corrections update the “last reviewed” date on the affected guide.
Last updated: July 23, 2026