Ideal Weight Calculator

Ideal Body Weight Formulas

Multiple formulas exist for estimating ideal body weight:

• Devine (1974): Most commonly used in clinical settings
• Robinson (1983): Modification of Devine, more accurate for women
• Miller (1983): Allows slightly higher weights
• Hamwi (1964): Originally for dosage calculations

These are estimates. Body composition varies significantly between individuals.

How to Use the Ideal Weight Calculator

1. Select your unit system — metric (centimeters, kilograms) or imperial (inches, pounds).
2. Enter your height in the appropriate unit for your selected system.
3. Choose your gender — male or female. This affects the formula calculations since men and women have different body composition norms.
4. Click "Calculate" to see your ideal weight according to four established formulas: Devine, Robinson, Miller, and Hamwi.
5. Compare the results — each formula gives a slightly different target. The range across formulas represents a healthy spread rather than a single magic number.

Understanding Ideal Weight Formulas

The concept of "ideal body weight" dates back to the 1940s, when insurance actuary tables linked body weight to longevity. Over the decades, several formulas have been developed to estimate a healthy weight based on height and gender. The Devine formula (1974) is the most widely used in clinical settings: for men, IBW = 50 kg + 2.3 kg per inch over 5 feet; for women, IBW = 45.5 kg + 2.3 kg per inch over 5 feet. It was originally designed for drug dosing calculations.

The Robinson formula (1983) refined Devine's work using newer population data: men = 52 kg + 1.9 kg per inch over 5 feet; women = 49 kg + 1.7 kg per inch over 5 feet. The Miller formula (1983) produced lower estimates: men = 56.2 kg + 1.41 kg per inch; women = 53.1 kg + 1.36 kg per inch. The Hamwi formula (1964) was designed for medium-framed individuals: men = 48 kg + 2.7 kg per inch over 5 feet; women = 45.5 kg + 2.2 kg per inch, with adjustments for frame size.

It's important to understand that "ideal weight" is an estimate, not an absolute target. These formulas do not account for muscle mass, bone density, age, or body composition. A muscular athlete may weigh significantly more than their "ideal weight" yet be perfectly healthy. Similarly, older adults may benefit from being slightly above the calculated ideal. Use these numbers as a starting point for discussion with your healthcare provider, not as a rigid goal.