Our standards
Every article and calculator on this site aims to be accurate, current, clearly sourced and easy to understand. We describe the standard ABO/Rh model faithfully, state its limits explicitly, and avoid overstating what blood type can tell you.
Sourcing
We rely on primary and authoritative secondary sources: national blood services (American Red Cross), government health libraries (MedlinePlus), professional bodies (ACOG) and peer-reviewed journals. Sources are listed at the end of each article and collected on the sources page. Where evidence is weak or contested, as with blood type personality and diet theories, we say so.
Review
Content is written and fact-checked by our editorial team against the sources cited. We do not currently claim independent clinical review; pages will display a reviewer byline only when a named, credentialed reviewer has checked them.
Calculator accuracy
Calculation logic is implemented as a standalone, tested library. Tests cover every ABO and Rh parent combination, probability ranges, unknown inputs, reverse (parent) lookups and compatibility rules. Results are reported as ranges when parental genotypes are ambiguous rather than as misleading single figures.
Updates
Each page shows its publication and last-updated dates. We review content when guidelines change or when readers report an issue.
Advertising
Advertising is served by Google AdSense and is labelled. Advertisers have no input into content, and we do not publish sponsored articles or accept payment for placement or recommendations.
Corrections
If you find an error, please contact us. We correct factual errors promptly and note substantive changes by updating the page date.