About PaydownBase

PaydownBase is a browser-based toolkit for US households planning debt payoff, credit card interest, and loan payments. Compare snowball and avalanche paths, estimate auto loan costs, and see total interest before you commit — without signing up or sending balances to a server.

Everything runs in your browser. No account, no saved inputs, no email gate. Balances and loan amounts stay on your device unless you choose to share a link.

Where the numbers come from

Default APR presets follow Federal Reserve G.19 consumer credit averages and NY Fed household debt releases. Loan math uses standard fixed-rate PMT amortization documented on our methodology page — not scraped from lender marketing pages. Every assumption and simplification is listed on our data sources & methodology page. Rate presets and formulas were last verified in July 2026.

We also publish short guides that explain the concepts behind the calculators — useful if you want to understand snowball vs avalanche tradeoffs or why minimum payments stretch payoff for years — not a replacement for a financial advisor or loan officer.

What this is not

Not financial advice, not lending approval, not a debt settlement or relief service, and not a substitute for your lender's payoff quote. These are planning estimates — useful for comparing strategies and loan costs before you borrow or accelerate payments.

Contact & corrections

Found a wrong formula, stale Fed rate preset, or calculator bug? Email contact@paydownbase.com. We treat incorrect rate data and payoff math as urgent once verified against the published source.