Clinical & Hospital Pharmacy
BMI & Anthropometric Calculator
Calculates body mass index (BMI) with WHO or Asian-Pacific classification, plus ideal, adjusted and lean body weight and body surface area for drug dosing.
Body mass index (BMI)
24.5kg/m²
Normal Weight — Low Risk (Optimal Health Range)
Measurements
Biological sex (needed for IBW and lean body mass)
≈ 68.9 in
≈ 165.3 lbs
Try an example patient
Where this BMI sits
Position on the BMI spectrum and the healthy weight for this height.
Current weight is within the healthy physiological reference range.
Dosing weights & body composition
The weights pharmacokinetic dosing and creatinine clearance equations call for.
WHO weight classification
Adult BMI bands used by the WHO International setting.
| Classification | BMI (kg/m²) | Health risk |
|---|---|---|
| Severe Thinness | < 16.0 | Very High |
| Moderate Thinness | 16.0 – 16.9 | High |
| Mild Thinness | 17.0 – 18.4 | Moderate |
| Normal Weight | 18.5 – 24.9 | Low (Optimal) |
| Overweight (Pre-Obese) | 25.0 – 29.9 | Moderate |
| Obese Class I | 30.0 – 34.9 | High |
| Obese Class II | 35.0 – 39.9 | Very High |
| Obese Class III | ≥ 40.0 | Extremely High |
Asian-Pacific cut-offs: underweight < 18.5, normal 18.5–22.9, overweight 23–27.4, obese ≥ 27.5.
BMI = weight (kg) ÷ [height (m)]²
The Quetelet index. Weights in lbs and heights in inches are converted and rounded to 0.1 kg / 0.1 cm first; BMI is rounded to one decimal.
Devine IBW — male: 50.0 + 2.3 × (height in inches − 60)
Devine IBW — female: 45.5 + 2.3 × (height in inches − 60)
The usual ideal body weight for drug dosing and creatinine clearance.
Robinson IBW — male: 52 + 1.9 × (in − 60) · female: 49 + 1.7 × (in − 60)
Hamwi IBW — male: 48 + 2.7 × (in − 60) · female: 45.5 + 2.2 × (in − 60)
AdjBW = IBW + 0.4 × (actual weight − IBW)
Uses Devine IBW. If actual weight is at or below IBW, the actual weight is shown.
Boer LBM — male: 0.407 × weight (kg) + 0.267 × height (cm) − 19.2
Boer LBM — female: 0.252 × weight (kg) + 0.473 × height (cm) − 48.3
BSA (Mosteller) = √[height (cm) × weight (kg) ÷ 3600]
The healthy weight range is the weight that gives a BMI of 18.5 to 24.9 at this height.
Common questions
It depends on the drug. Many hydrophilic drugs and creatinine clearance use ideal body weight (IBW); aminoglycosides in obese patients use adjusted body weight; some drugs use actual or lean body weight; chemotherapy is often dosed by BSA. Always follow the drug's monograph.
Asian adults tend to carry more visceral fat and develop diabetes and cardiovascular disease at a lower BMI. The WHO Western Pacific Region criteria lower the overweight threshold to 23 and obese to 27.5 kg/m² to reflect that risk.
AdjBW is only meaningful when actual weight exceeds ideal body weight. If you weigh the same as or less than your Devine IBW, the calculator shows your actual weight.
Devine, Robinson and Hamwi were derived from different data sets and for different purposes. Devine is the one most drug-dosing references assume; the others are shown for comparison.
No. Children's BMI must be interpreted against age- and sex-specific percentile charts. The bands on this page are for adults.
Prepared by the PharmaWallah student team. Verify results with your textbook or instructor. Report an error · Editorial policy