Editorial policy

CheckedCalc calculators and articles are written, checked and corrected to the rules below. Everything published is the responsibility of The CheckedCalc editor, a mechanical design engineer.

Sources, in order of priority

Rank	Source	Example
1	Published standards, cited with number and edition	ISO 286-2:2010, VDI 2230 Part 1:2015
2	Recognised engineering textbooks, cited with edition	Shigley's Mechanical Engineering Design, 10th ed.
3	Peer-reviewed or society papers	SAE and ASME technical papers
4	Manufacturer data, only where no standard applies, and labelled as typical	Friction coefficients, material properties

Forums, other calculator sites and AI answers are never used as a source.

Verification

Check	Rule
Worked example per function	Every public function in a calculation engine is tested against at least one worked example with a cited source and a hand-checkable number.
Automated tests	903 tests at present. A change is published only when all pass.
Public record	The worked examples, expected values and computed values are listed on the validation page.
Stated limits	Each calculator lists its assumptions and where the method stops being valid.

Corrections

Step	What happens
Report	Email hello@checkedcalc.com. The contact page lists what to include.
Response	Acknowledged within 5 working days. A suspected calculation error is investigated first.
Fix	A confirmed error is fixed, a test is added that reproduces it, and the page is republished.
Record	The correction is noted in the changelog on the page concerned, with its date.

What the dates mean

Date	Meaning
Published	When the calculator first went live.
Last checked	When the method, the cited editions and the worked example were last reviewed, whether or not anything changed. A date is not updated for cosmetic edits.

Use of AI

Calculators and copy on CheckedCalc are drafted with AI assistance, including code, tests and text. Every page is then technically reviewed by the editor: the method against the cited source, the numbers against the worked example and the copy for accuracy. Pages are briefed and checked one at a time. No pages are generated in bulk, and every page carries an original element such as a worked example or a design note.

Independence and limits

Advertising, when shown, never influences which methods or products are described. Results are for evaluation and must be verified by a competent engineer before use in a design. See the terms of use.