BMI - Body Mass Index

Estimate your Body Mass Index (BMI) from height and weight. Add waist for a stronger health signal (WHtR).

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This calculator estimates your BMI (Body Mass Index) — a simple height-to-weight screening metric. BMI can be useful for broad population-level comparisons, but it does not directly measure body fat or muscle.

What BMI measures (and what it doesn’t)

  • Measures: weight relative to height (a rough risk-screening tool).
  • Doesn’t measure: body fat %, muscle mass, bone density, or where you store fat.

How to use it

  1. Enter your height and weight.
  2. Click Calculate to get your BMI and category (if shown).
  3. Use BMI as a general reference — not as your only progress metric.

BMI categories (general reference)

  • Underweight: below 18.5
  • Normal weight: 18.5–24.9
  • Overweight: 25.0–29.9
  • Obesity: 30.0 and above

Important note for lifters

If you lift and carry more muscle, BMI can label you as “overweight” even when your body fat is reasonable. For a better picture, use BMI alongside waist measurements, body fat % estimates, and progress photos.

What to use instead (if you want more precision)

  • Body Fat % / LBM: better for tracking composition changes.
  • Waist measurement: simple, high-signal health/progress metric.
  • Scale trend + performance: weekly averages + strength progression.

Note: Estimates for informational purposes only, not medical advice.