1. Our Editorial Mission

MolecularWeightCalculator.org exists to make quantitative chemistry faster, clearer and more accessible — for students doing homework at midnight, teachers preparing lessons, and lab professionals who just need a reliable number quickly.

Everything we publish follows three principles:

• Accuracy above all — a chemistry site that publishes wrong numbers is worse than no site at all;
• Clarity over jargon — if a first-year student can’t follow our explanation, we rewrite it;
• Teach, don’t just tell — every tool shows its working, and every article explains the why behind the what.

This policy covers all content on the Site — every calculator, article, table, worked example and guide, including all tools we add in the future.

2. Who Creates Our Content

All tools and articles are created, edited and reviewed under the supervision of our founder and chief editor:

If we ever publish guest or contributed content, it will be clearly bylined and will pass the same review process before going live. Learn more on our About page.

3. Sourcing Standards

We only build on authoritative, primary scientific sources:

• IUPAC — the sole source for the standard atomic weights used in every calculation on this Site;
• NIST Chemistry WebBook — cross-checking reference for compound data;
• PubChem (NIH) — verification of molecular weights for specific compounds;
• Peer-reviewed textbooks and university-level course materials for pedagogical explanations.

What we don’t do: cite anonymous blogs or content farms as sources, copy competitor content, or publish claims we cannot trace to a reliable reference. External links in articles point only to sources we would use ourselves.

4. Our Content Creation Process

Every article on the Site goes through five stages:

5. How Our Calculators Are Built & Tested

Tools carry a higher duty of care than articles — people act on their outputs. Our standards:

• Official data only: atomic masses come from current IUPAC standard atomic weights (conventional values), covering all 118 elements;
• Reference testing: before launch, every calculator is tested against a suite of known reference compounds — water (18.015), glucose (180.156), copper sulfate pentahydrate (249.68), potassium ferrocyanide (368.34) and others — including edge cases like hydrates, brackets and lowercase input;
• Transparent math: every result displays its step-by-step derivation so users can verify it independently;
• Input safety: ambiguous or invalid formulas produce clear error messages rather than silently wrong answers, and auto-corrections are always flagged to the user;
• Regression checks: when a tool is updated, the full reference test suite is run again before the update goes live.

6. Accuracy & Fact-Checking

• Every numeric claim in an article is checked against its primary source before publication;
• Worked examples are computed independently, then confirmed with our own tools;
• Where values depend on data that changes (IUPAC revisions), we state the data version we use;
• Uncertainty is disclosed honestly — our tools are accurate to ~4 significant figures with conventional atomic weights, and we say so rather than implying false precision.

7. Content Updates & Maintenance

• Atomic mass data is reviewed against IUPAC’s latest recommendations and updated when IUPAC publishes revisions;
• Articles are reviewed periodically and refreshed when science, best practice or reader feedback warrants it;
• Tools receive fixes and improvements continuously — many driven directly by user suggestions;
• Substantive updates to an article are reflected in its dating; trivial fixes (typos, formatting) are not.

8. Editorial Independence & Advertising

The Site may display advertising (e.g. Google AdSense) to stay free. Our firewall between ads and content is absolute:

• Advertisers have zero input into our tools, articles, examples or data;
• We do not accept payment for coverage, rankings, mentions or “sponsored accuracy”;
• Ads are visually distinct from content and never disguised as editorial material;
• If we ever publish sponsored or affiliate content in the future, it will be clearly and conspicuously labeled.

9. Use of Technology & AI Tools

We use modern software tools — including AI-assisted drafting and coding aids — the way a professional workshop uses power tools: to work faster, never to skip quality control. Our rules:

• Every scientific claim, number and formula is verified by a human against primary sources regardless of how a draft was produced;
• Every calculator’s logic is human-reviewed and tested against reference compounds before launch;
• Nothing is ever published on an “auto-generate and forget” basis — final responsibility for all content rests with our named editor.

10. Corrections

When we get something wrong, we fix it quickly and honestly. Our full process — including how to report an error and how fast we respond — is documented in our dedicated Corrections Policy.

11. Reader Feedback

Our readers are our best reviewers. Several current features — including batch comparison — began as user suggestions. If you spot an error, find an explanation confusing, or want a new tool, please tell us. Every message is read, and useful suggestions are credited where the contributor wishes.

12. Contact the Editorial Team