Ideal Body Weight Calculator (Devine Formula)
Calculate your ideal body weight using the Devine formula — the most widely used clinical reference. Compare to your current weight and see your healthy range.
Quick Answer
Ideal Body Weight using the Devine formula: For men — 50 kg + 2.3 kg per inch over 5 feet. For women — 45.5 kg + 2.3 kg per inch over 5 feet. The ±10% healthy range accounts for frame size variation. IBW is a clinical reference point, not a strict personal target.
The Devine Formula: Origins and Use
The Devine formula was developed in 1974 by Dr B.J. Devine, initially for calculating medication doses in obese patients — not as a personal weight target. Despite this clinical origin, it became the most widely referenced formula for ideal body weight in hospitals, pharmacies, and medical literature worldwide. For men: IBW (kg) = 50 + 2.3 × (height in inches − 60). For women: IBW (kg) = 45.5 + 2.3 × (height in inches − 60).
Our calculator applies the ±10% range recommended by most clinical guidelines to account for natural variation in bone structure, frame size, and muscle mass. A petite-framed woman and a large-framed woman of the same height will have meaningfully different healthy weights — the ±10% range captures this natural variation.
How to Interpret Your Result
Your ideal body weight result is a clinical reference point, not an aesthetic goal or a medical prescription. It represents the weight associated with optimal organ function and minimal drug dosing error in a population-level context. Treat it as a rough benchmark — one data point among several — rather than a target to chase at the expense of muscle mass or overall wellbeing.
It is entirely possible to be above your Devine formula IBW and be metabolically healthy — particularly if the excess weight is muscle mass rather than fat. Conversely, it is possible to be at or below your IBW but carry excess visceral fat and have poor metabolic markers. This is why body fat percentage, waist-to-hip ratio, and metabolic blood markers provide a more complete picture than any single weight target.
Better Metrics for Goal Setting
If you are using your IBW to set a weight loss target, consider framing your goal around body composition instead. Rather than "lose 10 kg to reach ideal weight," a more meaningful target might be "reduce body fat from 30% to 22% while maintaining muscle mass" — because this specifies what type of weight you want to lose and protects against the muscle loss that commonly accompanies calorie restriction without adequate protein and resistance training.
Use our Calorie Deficit Calculator to set a daily calorie target for reaching a weight goal, our Macro Calculator to ensure adequate protein throughout, and our Body Fat Calculator to track whether you are losing fat rather than muscle. This combination gives you a complete system rather than a single number to fixate on.
Clinical note
The Devine formula was designed for medication dosing, not personal health goals. A BMI in the healthy range (18.5–24.9) with good body composition metrics is a more clinically meaningful target than hitting a specific IBW number.