65.9
kg
145.4
lb
66.9
in
6.9
in
15.9
kg
59.3
kg
72.5
kg
65.9
kg
145.4
lb
66.9
in
6.9
in
15.9
kg
59.3
kg
72.5
kg
The Devine formula is arguably the most widely recognized and frequently applied ideal body weight (IBW) equation in modern medicine. Published by Dr. B.J. Devine in 1974, this formula was originally developed not for general health assessment, but for calculating appropriate drug dosages, specifically for the antibiotic gentamicin. Despite its pharmacological origins, the Devine formula became the de facto standard for estimating ideal body weight across clinical nutrition, respiratory therapy, and general medical practice.
The formula is elegantly simple: for males, ideal body weight equals 50 kilograms plus 2.3 kilograms for each inch of height over 5 feet; for females, the base is 45.5 kilograms with the same 2.3-kilogram increment. This linear relationship between height and ideal weight assumes a medium body frame and average body composition. The formula's simplicity is both its greatest strength, allowing rapid bedside calculations, and its primary limitation, as it does not account for age, ethnicity, frame size, or muscle mass.
In clinical practice, the Devine formula serves as the foundation for numerous medical calculations. Tidal volume settings in mechanical ventilation are typically based on 6-8 mL per kilogram of ideal body weight (Devine), making accurate IBW calculation critical for patients on ventilators. Renal dosing adjustments, nutritional assessments, and body composition indices all frequently reference Devine IBW. The Adjusted Body Weight calculation, used for obese patients, begins with Devine IBW as its baseline.
It is worth noting that the Devine formula was derived from observations and clinical experience rather than from a large-scale statistical analysis. Subsequent research by Robinson (1983) and Miller (1983) attempted to refine the formula using actuarial and population data, but the Devine formula persists as the standard largely due to its historical precedence and widespread integration into clinical protocols and medical software. Studies comparing the Devine formula to BMI-based healthy weight ranges show reasonable agreement for average-height individuals but increasing divergence at height extremes.
This calculator applies the Devine formula with automatic unit conversion from centimeters to inches. It displays results in both kilograms and pounds, along with a plus/minus 10% range that accounts for normal variation in body frame size. Use this tool for clinical calculations, fitness goal-setting, or as a reference point for discussing weight management with your healthcare provider. For the most comprehensive assessment, compare results with our multi-formula Ideal Weight Calculator and Body Frame Size Calculator.
The Devine formula calculates ideal body weight as: Males: IBW = 50 + 2.3 x (height in inches - 60) and Females: IBW = 45.5 + 2.3 x (height in inches - 60). Height in centimeters is converted to inches by dividing by 2.54. The formula assumes a base of 5 feet (60 inches) and adds 2.3 kg for each additional inch. A plus/minus 10% range accounts for body frame variation.
The Devine IBW represents the weight associated with optimal health outcomes for your height and gender, assuming a medium body frame. The 10% range (low to high) accommodates small and large frames respectively. If your actual weight is within this range, you are close to clinical ideal. Weights more than 20% above IBW may indicate clinical significance for drug dosing adjustments and nutritional interventions.
Inputs
Results
A 180 cm male has a Devine IBW of 75.0 kg (165.3 lbs), with a healthy range of 67.5-82.5 kg.
Inputs
Results
A 165 cm female has a Devine IBW of 57.0 kg (125.7 lbs), with a healthy range of 51.3-62.7 kg.
The Devine formula was published by Dr. B.J. Devine in 1974 in the journal Drug Intelligence and Clinical Pharmacy. It was originally designed for calculating gentamicin antibiotic dosages but became the most widely used ideal body weight formula in medicine.
Its simplicity, historical precedence, and widespread integration into clinical protocols make it the default IBW formula. It requires only height and gender, can be calculated mentally, and has been validated across decades of clinical use for drug dosing and medical calculations.
For a BMI of 22 (mid-normal range), the corresponding weight is similar to Devine IBW for average-height adults. However, they diverge at height extremes because Devine is linear while BMI uses a squared relationship with height. Devine may underestimate IBW for very tall people.
The Devine formula becomes less reliable for people under 5 feet (152 cm) because the formula yields the base weight (50 kg for men, 45.5 kg for women) at exactly 60 inches and does not subtract for shorter heights. Alternative methods may be more appropriate for very short individuals.
The 10% range accounts for natural variation in body frame size. People with smaller bone structures may be healthiest toward the lower end, while those with larger frames may be healthiest toward the upper end. Our Body Frame Size Calculator can help you determine your frame.
Males have a higher base weight (50 kg vs. 45.5 kg) reflecting physiological differences in muscle mass, bone density, and body composition between sexes. Males typically have 10-15% more lean mass than females of the same height.
Yes, the ARDSNet protocol and most ventilator management guidelines use Devine IBW to calculate tidal volumes (typically 6-8 mL/kg IBW). This is one of the most critical clinical applications of the Devine formula, as using actual body weight can lead to lung injury in obese patients.
The Devine formula gives pre-pregnancy ideal weight. During pregnancy, expected weight gain varies by trimester and pre-pregnancy BMI. Consult your obstetrician for appropriate pregnancy weight guidelines rather than using IBW formulas.
The Devine formula was developed primarily from Caucasian population data. It may not be equally accurate for all ethnic groups, as body composition and frame sizes vary across populations. Asian populations, for example, may have lower optimal weights at the same height.
No, IBW is a reference point, not a strict target. Health exists across a range of weights. Focus on overall health indicators including body composition, cardiovascular fitness, blood markers, and energy levels rather than a single number on the scale.
Roboculator Team
The Roboculator Team explains calculations, planning tools, and practical formulas in clear language for real-life situations.
How helpful was this calculator?
Be the first to rate!
Ideal Weight Calculator
Ideal Weight & Body Measurements
Ideal Body Weight (Robinson Formula)
Ideal Weight & Body Measurements
Ideal Body Weight (Miller Formula)
Ideal Weight & Body Measurements
Waist-to-Hip Ratio Calculator
Ideal Weight & Body Measurements
Waist-to-Height Ratio Calculator
Ideal Weight & Body Measurements
Ponderal Index Calculator
Ideal Weight & Body Measurements
