Editorial Policy & Methodology

Payoff Logic publishes financial calculators and explanatory guides. Because these are money topics, we hold the content to a standard we can defend: every number a tool produces comes from math we have tested, and every piece of reference data we prefill is cited to a named source with the date we last reviewed it. This page explains exactly how that works so you can judge the site for yourself.

How our calculators are built and verified

Each calculator runs on a small, dedicated math engine — for example, one for mortgage amortization, one for loan payoff, one for FHA and VA loans. That same engine code is exercised by an automated test suite that runs before anything ships. The tests check results two ways:

• Against known-correct reference examples — payments and balances computed independently (from lender tables, government worksheets, or published examples) that the engine must reproduce.
• Against closed-form identities — mathematical relationships that must always hold (for instance, that a full amortization schedule pays the balance to exactly zero), which catch errors a single spot-check would miss.

The engine that our automated tests verify is the same code that runs in your browser — we do not maintain a separate "display" formula that could drift from the tested one. All math runs on your device; nothing you type is sent to us or stored.

How we handle reference data

Some tools prefill real-world figures — state property-tax rates, typical home values, homeowners-insurance averages, vehicle sales-tax rules, and government loan parameters. For that data we follow three rules:

• Named sources, with dates. Each dataset records where it came from and the year it represents. See our Data Sources page for the full list.
• Defaults, not quotes. Prefilled figures are planning starting points, and every one of them stays editable — your county, your insurer, and today's rates will differ, so the tools are built to be overwritten with your real numbers.
• Scheduled review. Rate and average figures are dated so we — and you — can see their vintage at a glance and refresh them on a regular cadence.

Editorial independence

Payoff Logic is independent. We are not a lender, broker, or financial-advisory firm. No bank, lender, or advertiser pays to change a calculator result, alter a guide's conclusion, or receive favorable placement in our math. Advertising and any affiliate links are kept separate from — and never influence — the numbers a tool returns or the recommendations in a guide. Advertisers never see the values you enter.

Our correction policy

We would rather be accurate than look infallible. If you find a math error, a stale figure, or a claim that reads wrong, tell us and we will investigate. When we confirm a substantive error, we fix it promptly and update the affected page's review date. Corrections that change a result meaningfully are noted so the change is transparent, not silent.

Not financial advice

Everything here is for general educational purposes and is not financial, legal, or tax advice. Our tools show you the math behind a decision; the decision itself depends on your full situation and is best made with a qualified professional. See our full disclaimer and Terms of Use.

Questions or corrections

Spotted something, or want a calculator that doesn't exist yet? We read everything — get in touch.