🏋️ Health & Lifestyle
Ideal Weight Calculator
Find your healthy weight range using five different medical formulas — BMI range, Devine, Robinson, Miller, and Hamwi. See how your current weight compares. Free, no signup.
Calculate Ideal Weight
—
Healthy weight range (BMI 18.5–24.9)
Ideal weight by formula:
Which Ideal Weight Formula Is Most Accurate?
There is no single universally agreed-upon "ideal weight." Different formulas were derived from different populations at different times, which is why they give different results. Here's what each formula is based on:
- BMI range (18.5–24.9): The broadest and most clinically used range. Gives a range rather than a single number. Best for general population health screening.
- Devine Formula (1974): Originally developed to calculate drug dosing for obese patients. Males: 50kg + 2.3kg per inch over 5 feet. Females: 45.5kg + 2.3kg per inch over 5 feet.
- Robinson Formula (1983): A refinement of Devine. Males: 52kg + 1.9kg per inch over 5 feet. Females: 49kg + 1.7kg per inch over 5 feet. Most commonly used in clinical practice today.
- Miller Formula (1983): Males: 56.2kg + 1.41kg per inch over 5 feet. Females: 53.1kg + 1.36kg per inch over 5 feet. Tends to give higher targets than Robinson.
- Hamwi Formula (1964): Males: 48kg + 2.7kg per inch over 5 feet. Females: 45.5kg + 2.2kg per inch over 5 feet. Commonly used by registered dietitians.
In practice, a range is more useful than a single number. The consensus healthy weight range from the BMI formula (18.5–24.9) is the most clinically validated and widely accepted.
Frequently Asked Questions
Is ideal weight the same for men and women of the same height?
No. The formulas use different baselines for men and women because of differences in average body composition. Women naturally carry more essential body fat than men (12–15% vs 3–5%). At the same height, most formulas calculate a slightly lower ideal weight for women than for men.
Why are all the formulas different?
Each formula was derived from different populations, time periods, and purposes. The Devine formula was developed for drug dosing, not general health. The Robinson formula was developed as a correction. None were specifically designed to predict optimal health outcomes. The BMI-based range has the most epidemiological evidence behind it, though it has its own limitations.
What if I'm muscular? Will my ideal weight be wrong?
Yes. All weight-for-height formulas have the same limitation as BMI: they can't distinguish between fat and muscle. A muscular athlete may weigh significantly more than the "ideal weight" while having excellent health markers. Body composition (body fat percentage) is a more accurate assessment for athletic individuals.