Sources & Reference Library

Source hierarchy

We prefer current government and professional guidance, original peer-reviewed equations, and transparent arithmetic. Each tool links the references relevant to its own method.

• CDC and National Center for Health Statistics
• National Academies / Dietary Reference Intakes
• ACOG pregnancy-dating guidance
• American Heart Association general heart-rate guidance
• 2024 Compendium of Physical Activities
• Current U.S. Army and Navy policy sources where those tools are provided