BMI Calculator

Accurate Body Mass Index (BMI) calculator with metric and imperial units, healthy categories, and WHO-based interpretation.

Select units

How to Use This Calculator

Choose metric or imperial units, enter your weight and height, and tap Calculate. The calculator shows your BMI together with the WHO adult category so you can see how your body mass compares to standard ranges.

Methodology

Metric BMI is computed as weight (kg) divided by the square of height (m). Imperially we apply the 703 multiplier to compensate for pounds and inches. Results are rounded to one decimal place for readability.

  • Small variations in input (e.g., rounding height) can shift your category, so round cautiously.
  • BMI is a screening tool; it does not distinguish lean mass from fat mass.
  • Use WHO adult ranges: Underweight <18.5, Healthy 18.5–24.9, Overweight 25.0–29.9, Obesity ≥30.0.
Outputs are estimates based on WHO guidance. For clinical or sport-specific assessment, consult a healthcare or fitness professional.

Full original guide (expanded)

Audit: Complete

Formula (LaTeX) + variables + units

The original extraction indicated this section shows the formulas used by the calculator engine, plus variable definitions and units.

Formula (extracted LaTeX)
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Variables and units
  • No variables provided in audit spec.
Sources (authoritative):
Changelog
Version: 0.1.0-draft
Last code update: 2026-01-19
0.1.0-draft · 2026-01-19
  • Initial audit spec draft generated from HTML extraction (review required).
  • Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
  • Confirm sources are authoritative and relevant to the calculator methodology.
Verified by Ugo Candido on 2026-01-19
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Formulas

Metric BMI: BMI = weight (kg) ÷ [height (m)]².

Imperial BMI: BMI = 703 × weight (lb) ÷ [height (in)]².

Heights are converted from centimeters or feet/inches before applying the formula. Results round to one decimal place.

Citations
Changelog

0.1.0-draft — Initial audit spec draft generated from the HTML extraction.

  • Review the formulas and convert text-only expressions into LaTeX if needed.
  • Confirm sources are authoritative and relevant to this health metric.
✓ Verified by Ugo Candido Last Updated: 2026-01-19 Version 0.1.0-draft
Formulas
Version 1.5.0