Ideal Weight Calculator
Compare healthy target body weights across the Devine, Robinson, Miller, and Hamwi equations.
Parameters & Inputs
Summary & Breakdown
Medical Formula Comparison
About the Ideal Weight Calculator
There is no single universal "ideal" weight for every human being, as skeletal frame size, bone density, and muscle mass create natural variation among healthy individuals.
However, clinical medicine utilizes historical benchmark formulas€”such as the Devine, Robinson, Miller, and Hamwi equations€”to establish baseline medication dosages, mechanical ventilation tidal volumes, and therapeutic nutrition targets.
This calculator contrasts all four clinical standards alongside the World Health Organization BMI healthy boundary, giving you an evidence-based target window rather than an arbitrary single digit.
How the Calculations Work
Computes ideal body weight using inches over 5 feet (60 inches) multiplied by formula-specific coefficients for each biological sex.
Devine: Men: 50.0 kg + 2.3 kg/inch > 5ft | Women: 45.5 kg + 2.3 kg/inch > 5ft
Variables & Definitions
- 5 ft baseline: 60 inches (152.4 cm)
- Devine: 50 kg (men) or 45.5 kg (women) + 2.3 kg per inch over 5 ft
- Robinson: 52 kg (men) or 49 kg (women) + 1.9/1.7 kg per inch over 5 ft
- Hamwi: 48 kg (men) or 45.5 kg (women) + 2.7/2.2 kg per inch over 5 ft
For a 175 cm (68.9 inches) tall male: Height over 5 feet is 8.9 inches. Devine formula: 50 + (2.3 * 8.9) = 50 + 20.47 = 70.5 kg (155.4 lbs).
Key Terms Explained
Ideal Body Weight (IBW)
A clinical benchmark used primarily in pharmacokinetics to determine safe drug clearance dosages.
Devine Formula
Formulated by Dr. Ben Devine in 1974 to standardize theophylline dosage calculations, now the clinical standard.
Skeletal Frame Size
Wrist circumference relative to height (small, medium, large frame), adjusting ideal weight by +/- 10%.
Body Composition
The ratio of fat mass to lean muscle tissue, which often makes muscular athletes weigh more than IBW formulas predict.
Practical Tips & Pitfalls to Avoid
View results as a healthy range
Aim for a 5-7 kg range rather than obsessing over a single rigid number on the scale.
Account for muscle development
If you lift weights regularly, your healthy body weight will naturally exceed Devine formula outputs.
Combine with waist circumference
A waist circumference under 94 cm (men) or 80 cm (women) indicates healthy abdominal fat levels.
Focus on performance metrics
Stamina, cardiovascular markers, and blood pressure reflect true health better than scale weight alone.
Frequently Asked Questions
The Devine formula is the most widely adopted standard across hospital pharmacology and clinical trials worldwide.
Each researcher evaluated distinct demographic study cohorts and prioritized different regression curves between height and health outcomes.
For heights below 5 feet (152.4 cm), the formulas subtract the incremental rate per inch below 60 inches.
While clinical IBW formulas do not adjust for age, research suggests a slightly higher BMI (25-27) is protective in adults over 65.
Yes. Individuals with high muscle mass, strong bone density, and low visceral fat can be in peak health above textbook IBW targets.