Body Composition Adjusted BMI Calculator

Estimate how lean mass influences your body mass index by weighting the classic BMI formula with your measured body fat percentage. The output shows both the adjusted BMI and the traditional BMI so you can discuss discrepancies with coaches, physicians, or clients.

Enter current body mass in kilograms. For pounds, divide by 2.205 before entering.
Measure standing height without shoes. The calculator converts centimetres to metres automatically.
Use the most recent reading from bioimpedance, DEXA, Bod Pod, or skinfold testing.

Informational tool only. Do not use as a substitute for professional medical evaluation.

Examples

  • 72.5 kg at 178 cm with 18% body fat ⇒ Adjusted BMI 18.2 | Standard BMI 22.9.
  • 90 kg at 182 cm with 12% body fat ⇒ Adjusted BMI 19.4 | Standard BMI 27.1 (muscular build).
  • 64 kg at 168 cm with 30% body fat ⇒ Adjusted BMI 16.5 | Standard BMI 22.7 (higher adiposity).
  • 82 kg at 170 cm with 22% body fat ⇒ Adjusted BMI 18.6 | Standard BMI 28.4, signalling recomposition progress.

FAQ

Why is body fat capped at 60%?

Extremely high entries can distort the formula and typically fall outside clinically observed ranges, so the calculator constrains inputs for stability.

How should athletes interpret this number?

An adjusted BMI close to standard BMI suggests body fat is already moderate. A noticeably lower adjusted BMI indicates higher lean mass relative to classic BMI thresholds.

Does hydration change the result?

Hydration shifts can influence body fat readings by a few percentage points. Measure under similar conditions (morning, fasted) for trend tracking.

Is this a medical diagnosis?

No. Use it as a coaching or self-tracking aid and consult healthcare professionals for personalised assessments.

Additional Information

  • Formula: Adjusted BMI = Classic BMI × (1 − Body fat fraction). The calculation reduces the influence of adipose tissue when interpreting body mass index.
  • Input recency matters—use body fat readings captured within the past 30 days to avoid skewed comparisons during intense training blocks or cutting phases.
  • For a holistic assessment, pair the results with waist-to-height ratio, resting heart rate, or VO₂ max estimates.

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