Editorial Standards & Methodology

Every calculator and article on Number Convertis built to help you make a decision with confidence. This page explains exactly how we create our tools, where the numbers come from, how we check them, and what we do when something is wrong. We'd rather be transparent about our process than ask you to take our results on faith.

How we build our calculators

Each tool starts with the underlying formula or standard that governs the calculation — for example, the compound-interest formula, a published tax bracket, an actuarial table, or an official unit-conversion factor. We implement that formula directly in code so the math is exact and deterministic: the same inputs always produce the same result, and nothing is rounded away behind the scenes. Where a calculation depends on assumptions (such as compounding frequency or inflation), we expose those assumptions as inputs you can change rather than hiding them.

Data sources

When a tool relies on external figures — tax rates, contribution limits, conversion constants, statistical averages — we draw from primary and authoritative sources such as government agencies, standards bodies, and official publications. Many of our tools list the specific sources used directly on the page under “Sources” or “References,” and we are actively expanding source citations across the whole library. If a figure changes (for instance, a new tax year), we update the tool and the “Last updated” date shown on the page reflects that change.

Accuracy and testing

We verify calculators against worked examples and known reference values, and we run automated quality checks across the site that test tools with normal, edge-case, zero, negative, and very large inputs to catch errors, broken states, and nonsensical output before they reach you. No automated process is perfect, which is why reader-reported corrections are an important part of how we keep results accurate.

Our use of AI

We use AI tools to help draft explanatory content and accelerate development. AI is an assistant in our process, not the final authority: calculation logic is implemented in code and checked against source formulas, and supporting content is reviewed and edited before it is published. We do not publish AI output unchecked, and we treat factual accuracy — especially for the financial, health, and scientific topics our tools cover — as something to be verified, not assumed.

Editorial independence

Number Convertis free to use and supported by advertising. Advertising revenue never influences the results a calculator produces or the guidance in our content. Our tools are informational and educational and are not a substitute for advice from a qualified professional — see our Disclaimer for details.

Corrections policy

If you believe a calculation, figure, or statement is wrong or out of date, please tell us. We prioritise accuracy corrections, investigate promptly, and update the tool or article along with its “Last updated” date. You can report an issue any time via our Contact page or by emailing contact@numberconvert.com.