Editorial policy

Health content earns trust through process. This is ours.

Sources

Factual claims are drawn from established medical institutions — the American College of Obstetricians and Gynecologists, Mayo Clinic, Cleveland Clinic, the NHS, and U.S. National Institutes of Health — and cited at the bottom of each guide. We do not cite forums, anonymous claims or manufacturer marketing.

Writing and review

Articles are drafted by our editorial team, then pass independent medical review before publication. Every page carries a byline, a publication date and a last-reviewed date. Independent medical reviewer onboarding is in progress; until it completes, pages state their review status plainly rather than implying a credential we do not yet have.

Updates

Guides are re-reviewed at least every nine months and after material new guidance; tools are re-verified yearly. Every page keeps an update history. Readers can report errors to contact@onlineperiodcalculator.com and we log corrections.

Independence

Editorial content is not influenced by advertisers or affiliates. Where we ever link to commercial products, the link is labeled. Our calculators' formulas and their limits are published on the methodology page for anyone to inspect.