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Ideal Weight Calculator

Health Updated 2025 100% Private

Determine your ideal body weight using four established formulas: Devine, Robinson, Miller, and Hamwi. Compare results and find your healthy weight range based on height and gender.

Ideal Weight Calculator

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What is Ideal Body Weight?

Ideal body weight (IBW) is a concept developed by healthcare professionals to estimate a healthy weight range for individuals based on their height and gender. Unlike BMI, which is a ratio of weight to height, ideal weight formulas aim to identify a specific weight that is associated with optimal health outcomes and longest life expectancy. These formulas were originally developed for clinical use — calculating medication dosages, estimating nutritional needs, and assessing health risks — but have become popular for personal health assessment as well.

Several formulas have been developed over the decades, each based on different population data and methodologies. The Devine formula, introduced in 1974, is the most widely used in clinical practice and was originally designed for drug dosing calculations. The Robinson (1983) and Miller (1983) formulas were developed as refinements of Devine, using updated population data. The Hamwi formula, dating back to 1964, is older but still referenced in nutritional assessments. Each formula typically gives slightly different results, which is why our calculator presents all four rather than selecting just one.

It is important to understand that ideal weight is a statistical concept, not a universal truth. The formulas were developed using population averages and do not account for individual variations in body frame size, muscle mass, age, ethnicity, or overall health status. A muscular athlete may weigh significantly more than their "ideal" weight while being in excellent health. Similarly, older adults may have a different healthy weight range than younger people of the same height. Use ideal weight as a general reference point, not as an absolute target that must be achieved.

The Four Ideal Weight Formulas

All formulas use height in inches above 5 feet (60 inches). For example, someone 5'8" (68 inches) has 8 inches over 5 feet.

Ideal Weight Formulas Devine: Men = 50 + 2.3h, Women = 45.5 + 2.3h
Robinson: Men = 52 + 1.9h, Women = 49 + 1.7h
Miller: Men = 56.2 + 1.41h, Women = 53.1 + 1.36h
Hamwi: Men = 48 + 2.7h, Women = 45.5 + 2.2h

Where h = inches over 5 feet (result in kg)

Ideal Weight FAQs

What is my ideal body weight?
Ideal body weight varies by formula, but generally falls within a range rather than a single number. Our calculator shows four established formulas. For most people, a healthy BMI range (18.5-24.9) translates to a weight range that serves as a practical target.
Which ideal weight formula is best?
The Devine formula is most commonly used in clinical settings. The Robinson and Miller formulas are refinements of Devine. The Hamwi formula is older but still used. Each gives slightly different results; the range across all four is more meaningful than any single number.
Does frame size affect ideal weight?
Yes, people with larger bone frames naturally weigh more. The Hamwi formula adjusts for frame size: add 10% for large frame, subtract 10% for small frame. Frame size can be estimated by wrist circumference relative to height.
Should I aim for my ideal weight?
Use ideal weight as a general guide, not an absolute target. Body composition (muscle vs fat), fitness level, and overall health matter more than hitting a specific number. Some people are healthier slightly above their "ideal" weight if they are muscular and active.
Why do formulas give different results?
Each formula was developed using different populations and methodologies. Devine (1974) was based on insurance data. Robinson (1983) and Miller (1983) refined Devine using newer data. Hamwi (1964) predates the others. The variation shows there is no single "correct" ideal weight.
Is ideal weight relevant for athletes?
Not particularly. Athletes often weigh more than their "ideal" due to high muscle mass. A muscular 180 lb person at 15% body fat is healthier than a non-athletic 160 lb person at 25% body fat, even if 160 is the "ideal." Focus on body composition and performance, not scale weight.