Calculated using standard mathematical and industry formulas.
Ideal body weight (IBW) is estimated using established clinical equations developed for medical drug dosing and nutritional standards, alongside the World Health Organization healthy BMI benchmark (18.5 to 24.9 kg/m²). This calculator compares results from the Devine, Robinson, Miller, and Hamwi formulas to give an accurate, realistic target weight range.
How to use this calculator?
Choose your unit system (metric or imperial) and biological sex.
Enter your height.
Read your recommended ideal weight and compare the four clinical formulas (Devine, Hamwi, Miller, Robinson).
Review the WHO healthy weight range (BMI 18.5–24.9) for your height.
Formula & calculation method
Devine, Hamwi, Miller, Robinson & WHO BMI Equations
Devine (Men): IBW (kg) = 50 + 2.3 × (Height in inches − 60); Devine (Women): IBW (kg) = 45.5 + 2.3 × (Height in inches − 60); Healthy WHO Range: Min = 18.5 × Height(m)², Max = 24.9 × Height(m)²
Inches over 60 = height in inches minus 60. Values in kg, converted to lb when imperial units are selected.
Step-by-step calculation example
Male 175cm (5 ft 9 in, 69 inches) → Devine: 70.7 kg (155.9 lb), Hamwi: 72.3 kg, Miller: 68.7 kg, Robinson: 69.1 kg. WHO Range: 56.7–76.3 kg.
Key insights to remember
The Devine formula is the most widely used medical reference for dosing medications based on ideal body weight.
Ideal weight formulas provide a reference target for average body frame sizes and do not account for heavy athletic muscle mass.
The WHO BMI range (18.5–24.9) provides a broader, population-validated healthy weight band.
For individuals under 5 feet (152 cm), formulas scale baseline values linearly per inch below 5 ft.
Maintaining a body weight within the WHO range correlates with a lower incidence of cardiovascular disease and metabolic disorders.
How to interpret your results?
Comparing the 4 Medical Formulas
Devine (1974) is the clinical standard in pharmacology. Robinson (1983) and Miller (1983) updated coefficients for modern populations, while Hamwi (1964) is popular in clinical dietetics.
Frame Size Adjustments
Wrist circumference determines skeletal frame size (small, medium, large). Individuals with large bone structures can healthily add 5% to 10% to baseline target weights.
Expert advice & guidance
💡 Target weight tip: Aim for a sustainable healthy weight range rather than a single rigid number. A 5 to 10 lb margin accommodates daily water fluctuations, muscle growth, and natural seasonal variations without compromising metabolic vitality.
Frequently asked questions
How much should a 5'9 or 5'10 guy weigh according to medical standards?
For an adult male who is 5'9" (175 cm), the healthy ideal weight range is 144 to 176 lbs (65 to 80 kg) according to WHO BMI standards (18.5–24.9), with the Devine formula centering ideal weight at 160 lbs (72.5 kg). For a 5'10" male (178 cm), the healthy range is 149 to 183 lbs (67.5 to 83 kg).
What is the average weight for teenagers and children (10 to 15 years old)?
According to CDC growth charts: the 50th percentile average weight for a 10-year-old is roughly 70 lbs (32 kg); for an 11-year-old it is 79 lbs (36 kg); for a 13-year-old girl, average weight is approximately 101 lbs (46 kg); and for a 15-year-old teen, average weight ranges between 115 and 130 lbs (52 to 59 kg).
What is the Devine formula and how does it calculate ideal weight?
Developed by Dr. Ben Devine in 1974, the formula assigns a baseline weight for a 5-foot height (50 kg for men, 45.5 kg for women) and adds 2.3 kg for every additional inch above 60 inches. It remains the gold standard in hospitals for calculating dosage of hydrophilic medications.
Is BMI outdated for determining ideal body weight?
While BMI is a reliable population-level screening tool, it does not account for muscle mass, bone density, or fat distribution. Muscular athletes often register as 'overweight' on BMI charts despite possessing low body fat and exceptional cardiovascular biomarkers.
What factors cause natural daily body weight fluctuations?
Normal human body weight fluctuates by 2 to 5 lbs (1 to 2.5 kg) within a single 24-hour period. Key drivers include fluid retention from sodium intake, glycogen replenishment (each gram of stored carb binds 3 to 4 grams of water), digestion status, and hormonal cycles.
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