Ideal Weight Calculator

The Ideal Weight Calculator is a tool designed to estimate a person’s ideal body weight using various established formulas, including those developed by Robinson (1983), Miller (1983), Devine (1974), and Hamwi (1964), as well as considering the Healthy BMI Range. Users input their age, sex, and height, and the calculator provides estimates in both kilograms and pounds. These calculations offer different perspectives on what an ideal weight might be, reflecting variations in body composition and health recommendations. The output aims to guide individuals in understanding weight targets that could be considered healthy based on their specific parameters. 

Ideal Weight Calculator

Guide to Using the Ideal Weight Calculator

The Ideal Weight Calculator is designed to provide individuals with an estimate of their ideal body weight based on several recognized formulas. This guide will take you through how the calculator works, the significance of each formula, and how to interpret the results.

How It Works

Upon accessing the calculator, users are prompted to enter three key pieces of information: age, sex, and height. These inputs are essential for the following reasons:

  • Age: While the calculator does not adjust the outcome based on age directly, it’s important for users to acknowledge that ideal body weight can vary with age.
  • Sex: Biological sex is factored into the formulas, as men and women typically have different body compositions.
  • Height: All the formulas use height as a primary variable to calculate ideal weight, making it the most significant input.

Understanding the Formulas

  1. Robinson Formula (1983): Offers estimates that have been updated since the original 1964 Hamwi formula, providing a slightly more modern standard.

  2. Miller Formula (1983): Similar to the Robinson formula, it provides updated weights and is considered a bit more lenient than the Hamwi and Devine formulas.

  3. Devine Formula (1974): Was originally developed to calculate drug dosages. It uses a base weight and adds a specified amount per inch over a certain height.

  4. Hamwi Formula (1964): The oldest formula used for determining ideal body weight, originally developed to help with medication dosages.

  5. Healthy BMI Range: This calculation does not provide a specific weight but rather a range where the body mass index (BMI) is considered healthy (18.5 to 24.9).

Interpreting the Results

After submitting your information, the calculator will display your ideal weight according to each formula, both in kilograms and pounds. You will see that different formulas may give slightly different results, reflecting the diversity in body types and the formulas’ intended applications. The Healthy BMI Range provides a broader perspective, suggesting a weight range that is considered healthy based on height.

Using the Information

The results can serve as a guide for understanding where your current weight falls in relation to various standards of ideal weight. Whether you’re looking to lose, gain, or maintain weight, these calculations can provide a starting point for setting realistic and healthy goals.


This Ideal Weight Calculator is intended for informational purposes only and is not designed to replace professional medical advice, diagnosis, or treatment. Always consult your doctor or a qualified healthcare provider with any questions you may have regarding your weight, health, or nutritional program. The use of this calculator should not substitute for medical advice, and the outcomes are general estimates that may not accurately reflect the ideal weight for your specific health condition or body type.

BMI Research

In the study “Reliability of Calculating Body Mass Index Centile” by V J Poustie, R L Smyth, and T J Cole, published in the European Journal of Clinical Nutrition (Volume 59, Pages 717-719, 2005), the authors explore the accuracy of two methods used for determining body mass index (BMI) centiles in children, a critical measure for assessing body fatness. The research involved 42 dietitians who calculated the BMI centiles of six children using either the Cole Calculator, a slide rule designed for this purpose, or a more traditional approach of manual calculation followed by plotting on a BMI centile chart. The findings revealed that the centile chart method yielded more reliable results compared to the Cole Calculator. The authors suggest that the greater reliability of the centile chart method may stem from its familiarity among dietitians. This study underscores the importance of selecting an appropriate method for calculating BMI centiles to ensure accurate assessment of body fatness in children. For more detailed insights into the study and its outcomes, the full article is accessible here.