Methodology & Editorial Standards

We make fast, free online tools. Most of them are calculators or converters, and the value of a calculator is only as good as the math behind it. We take that seriously and hold every tool to the standards described below.

How our calculators work

Every calculator on Lizely is built around a specific, named formula or standard rather than an ad-hoc approximation. Where a tool relies on a defined method — a mortgage amortization formula, a body-mass-index equation, a unit-conversion factor, a named statistical measure — we state that method plainly on the tool's page so you can see exactly what it computes.

We back those methods with real citations. Tools link out to authoritative references — the relevant Wikipedia article, the standards body that defines a unit or protocol, or a peer-reviewed source — as ordinary, followed links. We do not add citations for decoration; they point to sources you can check yourself.

Accuracy and testing

Before a tool ships, its math is locked by an automated “golden-value” test suite: a set of known inputs paired with independently verified expected outputs. If a change would make a calculator return a different number than the value we verified, the test fails and the change does not go live. This keeps results stable and guards against silent regressions as the site evolves.

Finance, health, and other YMYL tools

Some of our tools touch money, health, or other “your money or your life” topics — loan and mortgage calculators, tax and tip estimators, body-measurement tools, and similar. These tools are provided for general information only and produce estimates, not professional advice.

Not professional advice.Nothing on Lizely is financial, medical, legal, or tax advice, and using our tools does not create a professional relationship. Your real situation may differ from the assumptions a general calculator makes. For decisions that matter, consult a qualified professional — an accountant, financial adviser, doctor, or lawyer as appropriate.

Corrections

We want our tools to be right. If you spot a result that looks wrong, a formula that is misapplied, or a citation that no longer holds up, please tell us. Report it through our contact page and we will review it. Confirmed errors are fixed, and where a fix changes a result we add it to the golden-value tests so it stays fixed.

Who we are

Lizely is the brand and publisher behind this site: an independently run collection of free online tools. Our tools and supporting content are produced with AI assistance and reviewed under human direction against the standards on this page. We do not publish fabricated author credentials or invented experts — the responsible publisher is Lizely. You can reach us through our contact page.