Ideal Weight Calculator — Find Your Healthy Weight

The ideal weight calculator estimates a target body weight for your height and sex using four independently developed medical formulas: Robinson (1983), Miller (1983), Devine (1974), and Hamwi (1964). Each formula produces a single point estimate of the weight statistically associated with optimal health for a person of your stature and sex, and the calculator also shows the average across all four — a combined estimate that smooths out individual formula differences.

The concept of 'ideal weight' has a complex history in medicine. Early formulas like Hamwi (1964) and Devine (1974) were developed not as public health tools but for clinical pharmacokinetics — calculating appropriate drug doses based on lean body mass rather than total body weight. Robinson and Miller formulas appeared in the 1983 medical literature as refinements of this approach. All four were derived from actuarial and clinical data of predominantly mid-20th century Western populations, and each reflects slightly different assumptions about optimal body mass.

This calculator presents all four formulas simultaneously, allowing you to see the range of estimates. The spread between formulas — typically 4–8 kg for the same inputs — illustrates that 'ideal weight' is not a single scientifically precise number but a range, and that different clinical contexts have produced different answers. The average of the four provides a reasonable middle-ground estimate for general health reference and goal-setting purposes.

Example 1 — Male, 175 cm: Height in inches = 68.9". Inches over 5 feet = 8.9" Robinson: 52 + 1.9×8.9 = 68.9 kg Miller: 56.2 + 1.41×8.9 = 68.7 kg Devine: 50 + 2.3×8.9 = 70.5 kg Hamwi: 48 + 2.7×8.9 = 72.0 kg Average: (68.9+68.7+70.5+72.0) / 4 = 70.0 kg

Example 2 — Female, 165 cm: Height in inches = 64.96". Inches over 5 feet = 4.96" Robinson: 49 + 1.7×4.96 = 57.4 kg Miller: 53.1 + 1.36×4.96 = 59.8 kg Devine: 45.5 + 2.3×4.96 = 56.9 kg Hamwi: 45.5 + 2.2×4.96 = 56.4 kg Average: 57.6 kg

Comparison to BMI healthy range at 165 cm: BMI 18.5–24.9 → healthy weight range: 50.4–67.8 kg Average ideal weight (57.6 kg) falls in the middle of the range.

The pursuit of a healthy body weight is one of the most clinically significant health interventions available. Excess body weight is a primary risk factor for type 2 diabetes, cardiovascular disease, hypertension, sleep apnea, osteoarthritis, and at least 13 types of cancer according to the CDC and WHO. Achieving and maintaining a weight in the healthy range for your height reduces the risk of these conditions substantially — a 5–10% reduction in body weight in overweight individuals has been shown to lower blood pressure by 5–10 mmHg, improve insulin sensitivity, reduce LDL cholesterol, and cut cardiovascular disease risk by 10–15%.

Understanding where your current weight sits relative to population norms for your height and sex — which is exactly what these formulas provide — is the starting point for any rational weight management goal. Unlike BMI, which gives a range, the ideal weight formulas provide a single target number that many people find useful for concrete goal-setting. A 175 cm man who weighs 95 kg and sees a target of 70 kg from these formulas has a clear sense of the direction and approximate magnitude of change that would bring him into the historically defined 'optimal' weight zone.

For clinicians and healthcare professionals, ideal body weight formulas remain widely used for drug dosing calculations (the original purpose of the Devine formula), ventilator settings in ICUs, nutritional assessments, and bariatric surgery criteria. Understanding these formulas provides context for medical decisions and communications between patients and providers that reference 'ideal body weight' as a clinical parameter.

All four formulas were developed from research conducted primarily on mid-20th century Western adult populations, predominantly of European descent. Their applicability across different ethnic groups is not well-validated — research has shown that people of East Asian background develop metabolic risk at lower body weights and BMI values than these formulas would suggest, while some populations of African descent may have higher bone density and muscle mass that makes formula predictions too low. The formulas are not ethnically calibrated.

The most significant limitation is that all four formulas use only height and sex as inputs — they completely ignore age, bone density, body fat percentage, and muscle mass. A 65-year-old woman with naturally lower muscle mass will have the same formula output as a 25-year-old female athlete of the same height, despite very different healthy weight realities. For older adults, the ideal weight formula may actually underestimate a healthy weight since some evidence suggests BMI in the 25–27 range is associated with lower mortality in populations aged 65+.

These formulas produce a point estimate, not a range — which can create a false sense of precision. The scientifically honest conclusion from the spread between the four formulas (typically 4–8 kg) is that 'ideal weight' for any individual is a zone of approximately 5–10 kg, not a single number. Use the range between the lowest and highest formula output as a target zone rather than the average as a fixed target.