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Wellness Calculators

BMI, BMR, TDEE, body fat, pregnancy due date, and related wellness estimates. Educational only, not medical advice..

13 free tools available

Estimate body fat with the DoD/Army circumference method used in AR 600-9

Educational Widmark blood-alcohol estimate. Not for deciding whether to drive

Calculate body mass index from height and weight with WHO adult categories

Estimate basal metabolic rate with Mifflin–St Jeor, Harris–Benedict, or Katch–McArdle

Estimate body-fat percentage from Navy/Hodgdon–Beckett circumference measurements

Estimate BSA with Mosteller and Du Bois formulas from height and weight

Estimate daily calorie needs (TDEE) from BMR and activity level

Estimate pregnancy due date from last menstrual period using Naegele’s rule

Find the adult weight range that corresponds to BMI 18.5–24.9 for a given height

Compare Devine, Robinson, Miller, and Hamwi ideal-body-weight formulas

Estimate lean body mass with Boer, James, and Hume equations

Check adult BMI against the WHO overweight and obesity cutoffs

Check adult BMI against WHO underweight and thinness categories. Not an eating-disorder diagnosis

How to choose the right wellness calculators

Estimate BMI, BMR, TDEE, body fat, pregnancy due date, and related wellness numbers. Every result is educational, not a diagnosis.

Before you use a tool

  • BMI and body-fat formulas use population averages.
  • Pregnancy due dates from LMP are estimates, not ultrasound replacements.
  • Discuss health decisions with a qualified professional.

A practical workflow

Pick the wellness calculator that matches your question, enter height, weight, age, or dates with consistent units, and read the estimate alongside its limitations.