Ideal Weight Calculator: Finding Your Optimal Weight
"Ideal weight" is determined by multiple scientific formulas developed over decades of medical research. Our calculator uses four established formulas—Devine, Robinson, Miller, and Hamwi—to provide a range rather than a single number. This approach acknowledges that healthy weight varies based on body composition, frame size, and individual factors.
These formulas were originally developed for medical dosing calculations, where knowing a patient's ideal body weight helps determine appropriate medication amounts. They've since become standard references for weight goals. For body composition analysis, see our Body Fat Calculator and BMI Calculator.
Understanding the Formulas
Devine Formula (1974): The most widely used, originally for drug dosing. Men: 50 kg + 2.3 kg per inch over 5 feet. Women: 45.5 kg + 2.3 kg per inch over 5 feet. Simple and effective for average builds.
Robinson Formula (1983): A refinement of earlier methods. Uses slightly different increments for men (1.9 kg/inch) and women (1.7 kg/inch), producing values closer to Devine for most heights.
Miller Formula (1983): Produces higher ideal weights than other formulas, particularly for taller individuals. May be more realistic for larger-framed people.
Hamwi Formula (1964): One of the earliest, uses 2.7 kg/inch for men and 2.2 kg/inch for women. Often produces higher weights for tall individuals.
Frame Size Matters
Frame size significantly affects ideal weight. A small-framed person may be healthy at the lower end of the range, while a large-framed person might be healthy at higher weights. Measure your wrist circumference and compare to standard charts, or wrap your thumb and middle finger around your wrist—if they overlap, you're small-framed; don't touch, large-framed.
FAQ
Which formula should I use?
Consider the average of all four, adjusted for your frame size. If you're muscular, aim toward the higher end. The BMI-based range provides an additional reference point based on health outcomes research.
Why do formulas give different results?
Each was developed with different populations and purposes. The variation reflects the reality that "ideal weight" isn't one number—it's a range. Focus on overall health markers rather than hitting an exact weight.