BMI Calculator
Body Mass Index from height and weight (metric or imperial).
BMI, calories, pregnancy due dates, and body composition estimates — educational screening math, not clinical advice.
Educational screening estimates for body metrics, energy needs, and pregnancy timing — not a diagnosis or care plan.
Health-related calculators summarize common clinical screening formulas (such as BMI or Mifflin–St Jeor calorie estimates) so you can see a number quickly. They are educational only and are not a diagnosis, treatment plan, or substitute for a clinician.
Inputs like height, weight, age, and activity level change the result. Measure consistently, and read the limitations on each calculator page — especially if you are pregnant, under medical care, or using results to change diet or exercise.
Browse the tools below, then open any calculator for step-by-step guidance, the formula used, and a short example you can follow. We do not invent clinical claims or outcome statistics.
BMI in particular is easy to over-read; our BMI limitations guide, Navy body-fat method guide, and TDEE guide explain when a single number is a weak fit and how calorie estimates should be treated as ranges.
Body Mass Index from height and weight (metric or imperial).
Estimate daily calories (BMR/TDEE) using the Mifflin–St Jeor equation.
Estimated due date from the first day of your last menstrual period.
U.S. Navy method estimate using body measurements.