Editorial Policy

This page explains how each calculator on RK Calculator is made, checked and kept up to date.

1. Specification

Before a calculator is built, we write a specification: every input and option, every formula with a cited reference, how results are rounded, what the calculator can and can't do, and a set of test cases. We study widely used calculators on the same topic so that no useful feature is left out, but we write our own formulas, code and explanations.

2. Sources

Formulas and data come from authoritative sources such as standards bodies, government agencies and reference texts, for example unit definitions from NIST and ingredient weights from the US Department of Agriculture. Each calculator lists its sources, with the date data was taken where that matters. Where sources disagree, the calculator explains the choice it makes.

3. Testing

Test cases are worked out independently of the calculator's code, by hand or with separate software, and the calculator must reproduce every one of them, including edge cases and invalid inputs. Automated tests also check the pages in several browsers, on phones, and with accessibility tools.

4. Review before publication

A calculator is published only after the RK Calculator Team has reviewed and verified its formulas, test cases, limitations and explanation. Each tool page shows who reviewed it and when, and the reviewers page lists what has been reviewed. Until then, a calculator stays unpublished.

5. Use of AI

We use an AI coding assistant to help draft specifications, code, tests and explanations. Nothing it produces is published on trust: it has to pass the independent test cases and the RK Calculator Team's review first, and the team is accountable for the published result.

6. Updates and corrections

Each calculator shows its formula version. When we fix an error or change how something is calculated, we add a test case for it and update the version. See how to report an error.

7. Independence

If the site shows advertising in future, adverts will never change a result, and no calculator or explanation is paid for by an advertiser. Adverts will always be clearly separate from the calculator.