Ideal Body Weight Calculator (IBW & AdjBW)
Calculates reference body weight according to recognized clinical equations and determines Adjusted Body Weight (AdjBW) for clinical nutrition and medicine.
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Calculation
Result
- Devine Formula (Clinical Standard)
- 70.5 kg
- Average Across 4 Formulas
- 70.0 kg
- Robinson Formula (1983)
- 68.9 kg
- Miller Formula (1983)
- 68.7 kg
- Hamwi Formula (1964)
- 72.0 kg
- WHO Healthy Weight Range (BMI 18.5–24.9)
- 56.7 – 76.3 kg
- Adjusted Body Weight (AdjBW)
- 73.5 kg
- Percentage of Ideal Weight
- 110.7 %
Primary international benchmark for clinical protocols and pharmacotherapy
Balanced arithmetic mean of Devine, Robinson, Miller, and Hamwi
Body weight boundaries associated with minimal cardiovascular and all-cause mortality risk
Recommended baseline for calculating daily calories and protein in overweight individuals
Formulaic ideal weight is a statistical clinical reference. True individual targets must consider muscularity and visceral fat levels.
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How it is calculated
Medical ideal body weight equations were developed to standardize medication dosages, renal clearance clearance rates, and mechanical ventilation parameters. Unlike cosmetic weight charts, they benchmark physiological homeostasis and baseline metabolic function.
Formula
Devine (Men): 50 + 2.3 × (Height_in − 60); Devine (Women): 45.5 + 2.3 × (Height_in − 60); AdjBW = IBW + 0.4 × (Actual_Weight − IBW); Robinson: Men 52 + 1.9×in, Women 49 + 1.7×in.
Limits of the method
Formulas do not account for athletic muscular development or skeletal bone frame variation (hypersthenic vs. asthenic body types).
Sources of the method
- Devine B.J. Gentamicin therapy. Drug Intell Clin Pharm, 1974;8:650–655
- Robinson J.D. et al. Determination of ideal body weight for drug dosing. Am J Hosp Pharm, 1983;40(6):1016–1019
- Miller P.F. et al. Comparison of formulas for estimating ideal body weight. Am J Hosp Pharm, 1983;40:1622
- Hamwi G.J. Therapy: changing concepts in diabetes mellitus. In: Danowski T.S. (ed). Diabetes Mellitus: Diagnosis and Treatment. ADA, 1964:73–78
This calculation is for reference only and is not medical advice, a diagnosis or a prescription. If you have a medical condition, are pregnant, take medication or have any doubts, discuss the result with a physician or a qualified nutrition professional.
How to Properly Evaluate Your Target Body Weight
Compare the Devine formula with healthy BMI
The Devine formula typically aligns with a BMI of 21.5–22.5 kg/m²—the statistical center of the healthy weight continuum.
Use AdjBW if overweight
If your actual weight exceeds your ideal weight by more than 20% (BMI > 30), calculate your diet and protein intake using AdjBW rather than actual weight.
Account for skeletal bone structure
Individuals with broad bone frames (hypersthenic) naturally sit comfortably near the upper boundary of the WHO BMI range (23–24.9).
Calculation Examples for Men and Women
Overweight in a Male
Ideal weight by Devine = 73.2 kg (123% of IBW). Adjusted weight (AdjBW) = 79.9 kg.
Healthy Normal Weight
Ideal weight by Devine = 56.9 kg; by Robinson = 57.3 kg. Actual weight is 102% of IBW.
Tall Male Individual
Ideal weight by Devine = 84.0 kg; Hamwi = 87.5 kg. Actual weight is 117% of IBW.
The Origin of the Devine Formula
Dr. Ben Devine originally published his formula in 1974 for calculating clinical dosages of theophylline and aminoglycoside antibiotics. Over decades of clinical trials, it proved exceptionally accurate for metabolic modeling and was adopted by the WHO and CDC as the gold standard for ideal body weight.
Why Adjusted Body Weight (AdjBW) Matters
In an individual with excess adipose tissue, roughly 20–40% of surplus weight consists of supporting vascularized lean tissue and connective matrix, while the remaining 60–80% is metabolically inert triglycerides. AdjBW assigns a 0.4 correction factor, preventing hypercaloric diets that stall weight loss.
Comparison of Clinical Ideal Body Weight Formulas
| Equation | Base Weight (at 5 ft / 152.4 cm) | Increment per Additional Inch (2.54 cm) |
|---|---|---|
| Devine (1974) | Men: 50.0 kg / Women: 45.5 kg | 2.3 kg (Men & Women) |
| Robinson (1983) | Men: 52.0 kg / Women: 49.0 kg | Men: 1.9 kg / Women: 1.7 kg |
| Miller (1983) | Men: 56.2 kg / Women: 53.1 kg | Men: 1.41 kg / Women: 1.36 kg |
| Hamwi (1964) | Men: 48.0 kg / Women: 45.5 kg | Men: 2.7 kg / Women: 2.2 kg |
| WHO Range (BMI 18.5–24.9) | 18.5 × Height(m)² | Up to 24.9 × Height(m)² |
All formulas produce convergent values for individuals between 160 cm and 180 cm.
Frequently asked questions
Which ideal weight formula is considered the most authoritative?
The Devine formula (1974) is universally preferred in international medicine, pharmacology, and clinical dietetics.
Why don't clinical formulas factor in chronological age?
From a physiological perspective, cardiometabolic risk does not increase its acceptable threshold with age. While body fat often increases over time, the optimal biological reference point remains grounded in skeletal height.
What if my scale weight is 10 kg over ideal weight but I feel great?
If you train consistently and maintain a low body fat percentage (e.g. 10–14% in men, 18–22% in women), your excess weight reflects beneficial muscle mass. Use FFMI rather than IBW to evaluate your physique.
When is it necessary to use Adjusted Body Weight (AdjBW)?
Whenever actual body weight exceeds ideal body weight by more than 20% (BMI ≥ 30). Calculating diets or medical dosages by total weight would significantly overestimate energy needs.
Can ideal weight fall below the WHO healthy BMI floor?
In very short individuals (< 152 cm), older linear formulas can slightly underestimate weight. In such cases, the WHO BMI lower threshold (BMI 18.5) serves as the definitive safe minimum.
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What next
Formula breakdowns, biomarker reference ranges and nutrition articles with cited sources are in the NutriFit knowledge base.
Go to the knowledge base