Editorial policy

What you can expect from every calculator and article on FitAndFill.

How a calculator is made

• We write the formula down first and show it on the page with a worked example.
• The calculation code has automated tests, including rounding and invalid-input cases.
• Product figures (such as the yield of a bag of concrete or the coverage of a gallon of paint) come from manufacturer documents or other named sources, listed on the page with the date they were checked.
• Assumptions and limits are stated next to the tool, not hidden.

How a guide is made

• Every number in a guide is calculated by the same tested code the calculators use, so a guide and a calculator never disagree.
• Diagrams are drawn for the guide they appear in, with the same numbers as the worked examples.
• When a guide quotes a figure from someone else, such as a manufacturer's bag yield or a university extension's advice, the source is listed with the date we checked it. Anything we could not confirm is left out.

Review

A person reviews each page's formulas and sources before it is published and again when a source changes. The page shows who reviewed it and when. Figures that depend on changing data are re-checked on a schedule.

Use of AI tools

We may use AI tools to help draft or edit text and code. They do not replace review: the formulas are tested, the sources are checked by a person, and anything we cannot verify is not published.

Corrections

If you find a mistake, tell us. We confirm it against the formula and sources, fix confirmed errors and update the review date.

Advertising and independence

Some pages may show ads from third parties such as Google AdSense. Ads never change the result of a calculation, and nobody can pay us to change a result or a recommendation.