Ideal Weight Calculator

This calculator uses four widely-recognised formulas: Devine (1974), Robinson (1983), Miller (1983), and Hamwi (1964). Each formula estimates ideal body weight based on height and gender. We also show the healthy weight range based on Singapore's BMI thresholds of 18.5 to 23.0.

Singapore and the Asia-Pacific region use a lower upper threshold of 23.0 (versus the WHO standard of 25.0) because research shows Asians face higher health risks at lower BMI levels. The Health Promotion Board (HPB) recommends maintaining a BMI between 18.5 and 22.9 for optimal health.

Each formula was developed from different population studies and uses different mathematical approaches. Devine's formula is the most commonly used in clinical settings, while Robinson and Miller tend to give slightly higher estimates for shorter individuals. It is best to view the range across all four formulas rather than relying on a single number.

No. Ideal weight varies based on body composition, muscle mass, bone density, age, and overall health. These formulas provide useful reference ranges but should be considered alongside other metrics like body fat percentage, waist circumference, and overall fitness level.

None of the four classic formulas (Devine, Hamwi, Robinson, Miller) were developed specifically for Asian populations. They were derived from Western clinical samples in the 1960s to 1980s. For Singaporeans, the most practical and locally relevant approach is the BMI-based method using Singapore Health Promotion Board thresholds (healthy BMI 18.5 to 22.9), which accounts for the Asia-Pacific risk profile at lower BMI levels. The four formulas are still useful as a cross-reference range, particularly in clinical drug-dosing contexts.

Yes. Ideal weight formulas and BMI both treat the body as a single mass and do not distinguish between fat and lean tissue. A muscular person may weigh more than their formula ideal yet have a healthy or even very low body fat percentage. For example, a 175cm male rugby player could weigh 85kg with 12 percent body fat, well above his formula ideal of around 70kg but extremely healthy. In these cases, body fat percentage and waist circumference are more reliable health indicators than scale weight.

For population-level assessments, BMI is the more widely accepted clinical tool, including in Singapore where HPB and MOH use the 18.5 to 22.9 healthy range. Ideal weight formulas were originally designed for medication dosing rather than general health assessment. However, both BMI and ideal weight share the same limitation: neither accounts for body composition. The most complete picture combines BMI, waist circumference (HPB cutoff of 90cm for men and 80cm for women), and body fat percentage where available.