How MedMaths Calculators Are Built and Checked

MedMaths uses either published named equations or standard clinical arithmetic that is traceable to authoritative education and safety sources. Named equations are not rewritten or re-invented by MedMaths, and standard arithmetic methods are labelled as such rather than being falsely attributed to a formula creator.

Where multiple published equations exist for the same clinical measure — for example, the four BSA formulas — MedMaths presents them side by side rather than selecting one. The protocol or medication reference dictates which formula applies; that decision belongs to the clinician, prescriber, or pharmacist, not to the calculator.

Formulas are not added to MedMaths because they are popular or commonly memorised. They are added because they appear in verifiable clinical references and because the original publication can be identified and linked.

Each formula on MedMaths is traced to its original paper where one exists. The formula history stores each publication's title, author list, year, journal, DOI and PubMed ID (PMID). These fields are populated only when they can be confirmed from the publisher record, PubMed, or Crossref.

When a specific original paper cannot be confirmed — for example, where a formula is commonly attributed to a source that cannot be independently verified — the relevant field is left blank and the page states that verification is in progress. MedMaths does not reconstruct or estimate citation details.

Before a reference is added to the MedMaths formula history or a calculator page, each of the following is checked:

• The DOI resolves to the correct paper at the publisher.
• The PMID opens the matching record in PubMed.
• The author list in the stored record matches the paper's author list.
• External profile links (ORCID, institutional pages) unambiguously refer to the same individual and are not shared by another researcher with a similar name.

If any of these checks cannot be completed, the field is left blank rather than estimated. An honest absence of data is more useful than a plausible-looking incorrect link.

Every calculator on MedMaths has automated arithmetic checks that run before release. These checks compare known inputs with known expected results.

For example, one Mosteller BSA check uses a person 170 cm tall and weighing 70 kg. The expected result is exactly 1.818118685772619 m² to 12 decimal places. If the calculation no longer matches the expected value, the check fails.

Calculator-specific checks cover arithmetic, units, input boundaries, expected working and safety wording. A separate site-wide check verifies that calculator relationships and shared navigation remain consistent as the site changes.

A separate pre-publication check reviews page metadata, breadcrumbs, references, internal links, and calculator placement so the main calculation remains easy to reach.

MedMaths distinguishes clearly between three roles that must never be conflated:

Formula originally described by

The historical researcher(s) who published the original equation. These scientists have historical research profiles in the formula history directory. They are not affiliated with MedMaths, have not contributed to this website, and have not endorsed it. Attribution on calculator pages records formula provenance only — not endorsement, involvement, or review.

Written and maintained by

The MedMaths editorial contributor — George Lambroglou, RN. Calculator pages, Guides and educational content are written, checked and maintained by George under the current founder-led process. This is not labelled as independent clinical review. See the author profile for more detail.

Clinically reviewed by

A separate qualified clinical reviewer, only where that person has genuinely reviewed the specific page. MedMaths does not imply independent or external review where none has occurred.

MedMaths may use software automation and AI-assisted tools as production aids for tasks such as organising research notes, exploring wording options, writing or refactoring code, and identifying possible quality or consistency issues. These tools are not treated as clinical authorities, formula originators, authors, or independent reviewers.

A formula, clinical claim, reference, limitation, or calculator behaviour is not accepted simply because an automated or AI-assisted tool produced it. Source claims are checked against the cited material, calculator arithmetic is checked against known results, and the published content is approved through the founder-led MedMaths review process.

Content on MedMaths is reviewed when a relevant guideline changes, when a formula is superseded or its scope is redefined in the literature, or when an error is reported. Each page carries a "Last reviewed" date.

To report a potential error or suggest a correction, use the contact page or email medmaths.calc@gmail.com. Formula corrections go through the same calculation-test process as new calculators — a changed number must be verified against the source publication before the corresponding automated test is updated.