Ideal Body Weight Calculator (Devine Formula)

The Devine Formula was introduced by B.J. Devine in 1974. For males: IBW (kg) = 50 + 2.3 × (height in inches above 5 feet). For females: IBW (kg) = 45.5 + 2.3 × (height in inches above 5 feet). It was originally developed for drug dosing purposes in clinical settings.

Not exactly. Ideal body weight calculated via the Devine Formula is a clinical estimate, often used for medication dosing rather than fitness goals. A healthy weight range is typically considered ±10% of the IBW. For broader health assessments, BMI and body composition metrics are also useful.

The Devine Formula works best for adults of average build and height above 5 feet (152 cm). It may be less accurate for people who are very short, very tall, heavily muscled, or have a non-average body frame. Children and adolescents should use age-specific growth charts instead.

The original Devine Formula is designed for heights above 5 feet. For individuals below this threshold, the formula loses accuracy and may produce unrealistically low values. Some clinicians use a modified baseline or simply use the base value of 50 kg (male) or 45.5 kg (female) for heights at or below 5 feet.

Clinicians use IBW primarily for calculating drug doses, ventilator tidal volumes, and nutritional requirements where actual body weight might skew results — especially in obese patients. It provides a standardized reference weight independent of excess fat mass.

BMI (Body Mass Index) measures the ratio of weight to height squared and categorizes individuals as underweight, normal, overweight, or obese. IBW gives a single target weight based on height and sex. BMI is a screening tool, while IBW is more often used in clinical dosing calculations.

You can use it as a rough reference point, but the Devine Formula result shouldn't be treated as a personal weight loss target without medical guidance. Factors like muscle mass, bone density, age, and overall health all influence what weight is truly ideal for you as an individual.

Yes — other commonly used formulas include the Robinson Formula (1983), the Miller Formula (1983), and the Hamwi Formula (1964). Each produces slightly different results. The Devine Formula remains the most widely referenced in clinical pharmacology and critical care medicine.