Ideal weight formulas estimate a healthy target weight from your height, and the best-known is the Devine formula, published in 1974 — originally to calculate drug dosages, which is why it stuck around in medicine. For men: ideal weight = 50 kg + 2.3 kg for every inch over 5 feet. For women: 45.5 kg + 2.3 kg for every inch over 5 feet. Related formulas by Robinson, Miller, and Hamwi adjust the constants slightly, but they all agree on the core idea: taller frames healthily carry more weight, and the relationship is roughly linear across typical adult heights. These formulas describe a single 'ideal' number, which makes them easy to remember but less nuanced than range-based approaches.
Many clinicians prefer a healthy weight range derived from BMI cutoffs instead of a single number, because bodies legitimately vary. For any height, the BMI healthy band of 18.5 to 24.9 converts directly to a weight range: multiply 18.5 and 24.9 each by your height in meters squared. A 1.75 m person, for example, gets a range of about 56.7 to 76.3 kg — a span of nearly 20 kg that accommodates different builds, muscle mass, and bone structure. Wherever you land inside that range, other measures like waist circumference and body fat percentage refine the picture. The Devine number usually falls near the middle of the BMI range, so the two approaches corroborate rather than contradict each other.
Use the result as a compass heading, not a destination you must hit exactly. Muscle, bone density, age, and natural build all shift where your personal healthy weight sits, and no formula knows your frame size or medical history. If your target implies large or rapid weight change, plan it gradually — 0.5 to 1 kg per week is the sustainable rate — and involve a doctor or dietitian, especially with any medical condition. This calculator is informational only: a screening estimate to guide conversations with professionals, not a prescription.