Ideal Weight Calculator

What is Ideal Weight?

Ideal body weight (IBW) is a clinical estimate of the weight range most associated with good health outcomes for a person of a given height and gender. Unlike BMI, which uses a single formula, ideal weight has been calculated using several different clinical formulas developed over decades of medical research. No single formula is universally "correct" — each was developed for a specific purpose, and comparing across formulas gives a more complete picture than relying on any one alone.

It is important to understand that "ideal weight" is a range, not a single number. A healthy weight for your height may span 10–15kg depending on your body frame, muscle mass, and individual physiology. Use these figures as a reference point, not a rigid target.

How to Use This Ideal Weight Calculator

Select your gender and enter your height. The calculator instantly displays your ideal weight estimates from four validated clinical formulas — Devine, Robinson, Miller, and Hamwi — along with a composite recommended range. Switch between Metric and Imperial units at any time.

The Four Clinical Formulas Explained

Devine Formula

The most widely used formula in clinical medicine, originally developed by Dr. B.J. Devine in 1974 for pharmaceutical drug dosing calculations. It remains the standard reference in many hospital settings:

Robinson Formula

A 1983 refinement of the Devine formula by Robinson et al., designed to better represent typical body proportions:

Miller Formula

Developed by Miller et al. in 1983, this formula tends to produce slightly lower estimates than Devine and Robinson, and is sometimes preferred for individuals with smaller frames:

Hamwi Formula

Originally developed by Dr. G.J. Hamwi in 1964 for use in diabetes management, this formula is commonly used by dietitians and uses a slightly different base weight:

Body Frame Size — Why It Matters

All four formulas assume an average body frame. In practice, people vary in skeletal frame size — small, medium, or large — which affects healthy weight range. A simple way to estimate frame size is the wrist circumference method: measure the circumference of your wrist at the smallest point. For women of average height (around 160–170cm), a wrist under 14cm suggests a small frame; 14–15.2cm is medium; over 15.2cm is large. Adjust your ideal weight target by approximately 10% downward for small frames and 10% upward for large frames.

Ideal Weight vs BMI vs Body Fat

These three measures each tell you something different:

• Ideal Weight — target weight range based on height and gender using clinical formulas
• BMI — weight-to-height ratio classified into health categories — check with our BMI Calculator
• Body Fat % — actual proportion of body weight that is fat — most accurate measure — check with our Body Fat Calculator

Using all three together gives a much more complete picture than any single measure alone.

Setting a Realistic Weight Goal

If your current weight is above your ideal weight range, use our Calorie Deficit Calculator to calculate a safe daily calorie target. A deficit of 500 calories per day produces approximately 0.5kg of fat loss per week — placing you within your ideal weight range in a realistic, sustainable timeframe. Pair this with adequate protein from our Protein Calculator to preserve muscle during the process.

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