Ideal Weight Calculator — IBW by 5 Different Formulas
Unit System
Gender
About This Tool
The Ideal Weight Calculator estimates your healthy body weight based on height and gender using four classic formulas (Devine, Robinson, Miller, and Hamwi) alongside the standard healthy BMI weight range.
How to Use
- Select your preferred unit system and gender.
- Enter your height in centimeters or feet and inches.
- View the average ideal weight estimate instantly.
- Compare formula outcomes in the comparison grid and examine your healthy BMI-based weight range.
Detailed Explanation & Worked Example
An Ideal Body Weight (IBW) calculator determines an optimal weight based on height, gender, and age. The concept was initially introduced by doctor and researcher Devine in 1974 for medical dosage calculations, but it has since been widely adopted as a general standard for tracking fitness goals.
Ideal Body Weight Formulas
The four historical formulas utilize height in inches over 5 feet (152.4 cm) as the primary factor:
| Formula | Male Equation (Height > 5 ft) | Female Equation (Height > 5 ft) |
|---|---|---|
| Devine (1974) | 50.0 kg + 2.3 kg per inch | 45.5 kg + 2.3 kg per inch |
| Robinson (1983) | 52.0 kg + 1.9 kg per inch | 49.0 kg + 1.7 kg per inch |
| Miller (1983) | 56.2 kg + 1.41 kg per inch | 53.1 kg + 1.36 kg per inch |
| Hamwi (1964) | 48.0 kg + 2.7 kg per inch | 45.5 kg + 2.2 kg per inch |
BMI-Based Weight Range
While historical formulas offer specific numbers, the World Health Organization (WHO) recommends tracking a healthy range based on BMI (Body Mass Index) standards between 18.5 and 24.9. This provides a flexible weight range that accounts for natural biological variance, muscle definition, and body frame sizes.