Ideal Body Weight Calculator

This evidence-based calculator determines your ideal body weight range using multiple medical formulas (Devine, Robinson, Miller, and Hamwi). Compare different methods and find personalized weight ranges based on your height, gender, and frame size.

Medical Disclaimer: This tool provides general educational estimates. Consult a board-certified provider for personalized advice.

Contents

Units:
ft in

How to determine your frame size: Wrap your thumb and middle finger around your wrist. If they overlap, you likely have a small frame. If they touch, medium frame. If they don't touch, large frame.

How to Use the Ideal Body Weight Calculator

Follow these steps to determine your ideal body weight range based on medical guidelines:

  1. Select your gender: Male and female calculations use different formulas.
  2. Enter your height: Use either imperial (feet/inches) or metric (cm) units.
  3. Choose your frame size: Small, medium, or large based on wrist measurement.
  4. View your results: See the average of multiple medical formulas and a healthy range.

Understanding Your Results

  • Average Ideal Weight: The mean value across all formulas adjusted for your frame.
  • Healthy Weight Range: A 10% variation around your calculated ideal weight.
  • Formula Breakdown: Individual results from each medical formula.

All estimates are based on medical formulas developed by Devine, Robinson, Miller, and Hamwi. This is for general education and does not replace medical advice.

Frequently Asked Questions

What is ideal body weight (IBW)?

Ideal body weight (IBW) is a theoretical weight range associated with optimal health outcomes based on height, gender, and frame size. It was originally developed to help determine appropriate medication dosages but has since been used as a general health metric. Unlike BMI, IBW calculations factor in differences between male and female body composition and can be adjusted for frame size. These are evidence-based estimates derived from population studies, not absolute targets that everyone should achieve.

Which formula is most accurate for calculating ideal body weight?

There is no single "most accurate" formula, as each has strengths and limitations. The Devine formula (1974) is widely used in clinical settings, particularly for medication dosing. The Robinson formula (1983) tends to give slightly lower values. The Miller formula (1983) often provides the most conservative estimates. The Hamwi formula (1964) is one of the oldest and simplest methods. This calculator uses all four formulas and provides both an average and the range between them, giving you a more comprehensive picture than any single formula alone.

How does frame size affect ideal body weight?

Frame size accounts for variations in skeletal structure that aren't captured by height alone. People with larger frames naturally have heavier bone and muscle mass independent of body fat. In ideal weight calculations, small frames typically reduce the target weight by 10%, while large frames increase it by 10%. Frame size can be roughly estimated by measuring wrist circumference in relation to height, or by the thumb-middle finger overlap test around the wrist as described in the calculator instructions.

Is BMI or ideal body weight more accurate?

Neither metric is inherently "more accurate" - they serve different purposes. BMI (Body Mass Index) is simpler and useful for population-level statistics, but doesn't account for differences in muscle mass, bone density, or body composition. Ideal body weight formulas incorporate gender and can be adjusted for frame size, potentially making them more personalized. However, both metrics have significant limitations. For the most comprehensive assessment, these calculations should be considered alongside other health markers like waist circumference, body fat percentage, and metabolic health indicators.

How close should I be to my ideal body weight?

Being within 10-15% of your calculated ideal weight range is generally considered healthy for most people. However, the importance of achieving a specific number should not be overemphasized. Various factors including muscle mass, ethnicity, age, and individual health conditions may make different weights optimal for different people, even at the same height. Focus on overall health markers such as energy levels, blood pressure, cholesterol, and blood sugar control, rather than trying to achieve an exact weight number. Always consult with healthcare providers for personalized guidance.