Editorial Policy

This page describes how content on MegaTools is researched, written, reviewed, and corrected. It applies to every calculator page and every guide.

Sourcing#

Formulas and reference values come from primary sources: the organisation that defines the standard, publishes the guideline, or sets the rate.

In practice that means the World Health Organization and the National Institutes of Health for health formulas, NICE and equivalent national bodies for clinical thresholds, peer-reviewed papers for equations that originated in the literature, and the relevant tax or standards authority for anything jurisdiction-specific.

We do not source from other calculator sites, content aggregators, or AI summaries. Errors spread across the web by copying, and the only reliable defence is going back to the document that started the chain.

Every tool page lists its sources with working links. Where a source sits behind a paywall, we cite the abstract or the official record so the citation can still be verified.

Which formula we use#

Several common calculations have more than one accepted formula — basal metabolic rate is the clearest example, with the Harris-Benedict, Mifflin-St Jeor, and Katch-McArdle equations all in current use and all producing different answers.

Where this happens, the page states which equation it implements, why that one, and roughly how far the alternatives diverge. Hiding the choice would make the result look more definitive than it is.

Accuracy and rounding#

Every calculator is checked by hand against worked examples before publication, using the example calculations in the source document where the source provides them.

Rounding is done at the point of display, not during the calculation, so intermediate steps do not accumulate error. Where a result is sensitive to input precision — BMI shifts by roughly half a point per centimetre of height — the page says so.

What we do not publish#

We do not publish medical, financial, legal, or tax advice. The tools compute; they do not recommend.

We do not attribute content to reviewers who have not reviewed it. Fabricated credentials are common on health calculator sites — a physician's name attached to a page they have never seen. We would rather cite the WHO directly than invent a reviewer, and that is what these pages do.

We do not publish a tool without its explanatory content. The calculator and the explanation ship together or not at all.

Updates#

Pages carry a visible "last updated" date that reflects an actual change to the content. It is not refreshed automatically to make a page look current — a date that moves without the content moving is a lie told to a ranking algorithm at the reader's expense.

Pages are revisited when a source publishes revised guidance, when a rate or threshold changes, or when a reader reports a problem.

Corrections#

If you find an error — a wrong formula, a miscalculation, a broken edge case, a citation pointing at superseded guidance — tell us through the contact page and include the tool and the inputs you used.

Substantive corrections to a formula or a stated threshold are noted on the page. Fixing a typo is not, because a correction notice for a spelling mistake only makes real corrections harder to spot.

Advertising and independence#

MegaTools is funded by display advertising. Advertisers have no involvement in what any tool computes or what any page says, and no page is written to make a product look better than the arithmetic supports. Ads are never placed between a reader and a result.