BMI Calculator

BMI — Quick 8‑Section Guide

Fast way to interpret your Body Mass Index correctly and use it alongside other metrics.

1) Core idea

  • Metric: BMI = weight(kg) / height(m)²
  • US: BMI = 703 × weight(lb) / height(in)²

2) Flow

  • Enter age, gender, height, weight → we convert exactly (1 in = 2.54 cm; 1 lb = 0.45359237 kg)
  • We compute BMI and map it to WHO categories

3) Sanity checks

  • Height > 0; weight > 0; realistic adult ranges
  • Gauge capped to 0–50 BMI for legibility

4) Shortcuts

  • Toggle cm ↔ ft/in and kg ↔ lb in‑place
  • US mode uses the exact 703 factor

5) Pitfalls

  • Muscle vs fat: BMI can label athletes as overweight
  • Children/elderly: use age‑specific tools

6) Micro examples

  • 70 kg, 175 cm → 70 / 1.75² = 22.9
  • 154 lb, 69 in → 703×154/69² ≈ 22.7

7) Mini‑FAQ

  • Healthy adult range: 18.5–25 kg/m²
  • Better with context: pair with Body Fat and TDEE

8) Action tip

If your BMI is borderline, check body‑fat % and waist‑to‑height ratio before making big diet or training changes.

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