Where to start
BMI is the quick screening number, but it cannot tell muscle from fat — pair it with the body fat calculator for a truer picture. If your goal is weight change, the calorie (TDEE) calculator is the one that matters: it converts your BMR (calories burned at rest, via the Mifflin-St Jeor equation) into a daily target based on how active you actually are. These tools use the standard formulas clinicians use, but they are planning aids, not medical advice.
Frequently Asked Questions
Which formula do these calculators use?
The established standards: WHO ranges for BMI, the Mifflin-St Jeor equation for BMR and calories, the US Navy method for body fat, and the Devine formula for ideal weight — the same ones used in clinical practice.
Can I rely on these instead of a doctor?
No. They are accurate implementations of standard formulas, useful for tracking and planning, but they don't know your medical history. Consult a doctor before major diet or exercise changes.