Ideal Weight Calculator

Compare your ideal body weight across four trusted formulas — Devine, Robinson, Miller, and Hamwi.

Ideal Weight Calculator

Gender

Height

Frame Size

Understanding Ideal Body Weight

Ideal body weight (IBW) formulas estimate the weight most associated with good health for a given height. Originally developed for medical purposes — particularly drug dosing and insurance risk assessment — these formulas remain widely referenced. While no single number can define an "ideal" weight for everyone, comparing results from multiple formulas gives you a practical target range.

The Four Formulas

Devine (1974) — the most common in clinical settings. For men: 50 + 2.3 kg per inch over 5 ft. For women: 45.5 + 2.3 kg per inch over 5 ft. Robinson (1983) — slightly revised coefficients giving somewhat higher estimates. Miller (1983) — typically produces the lowest ideal weights of the four. Hamwi (1964) — the oldest formula, based on Metropolitan Life Insurance data, giving results in the mid-range.

Why Results Differ

Each formula was derived from different populations and time periods. The variation between them — often 5-15 lbs — actually provides a useful healthy weight range rather than a single target. Where you fall within that range depends on your body frame, muscle mass, and individual physiology. Athletes and heavily muscled individuals will typically exceed all four estimates while still being at a healthy weight.

Frame Size Impact

Body frame size significantly affects what a healthy weight looks like. A large-framed individual naturally carries more bone mass and may weigh 10% more than a medium-framed person at the same height and still be perfectly healthy. Small-framed individuals may weigh 10% less. The wrist circumference test is a simple way to estimate frame size: measure your wrist and compare to standard charts for your height and gender.

Disclaimer: This calculator is for informational purposes only and is not a substitute for professional medical advice. Always consult a healthcare provider for personalized health assessments.

Frequently Asked Questions

What is ideal body weight (IBW)?

Ideal body weight (IBW) is an estimated weight range considered healthiest for a given height. It was originally developed for medical dosage calculations and insurance risk tables. While no single number defines "ideal," these formulas provide useful reference points. Your actual healthiest weight depends on many factors including muscle mass, frame size, age, and overall body composition.

Why do the four formulas give different results?

Each formula was developed using different population data and assumptions. The Devine formula (1974) is the most widely used in medicine. Robinson (1983) tends to give slightly higher estimates. Miller (1983) typically produces the lowest values. Hamwi (1964) is the oldest and was based on insurance actuarial data. The range between formulas gives you a more realistic target window rather than a single fixed number.

How does frame size affect ideal weight?

Frame size — small, medium, or large — significantly impacts what a healthy weight looks like. A large-framed individual naturally carries more bone and muscle mass and will weigh more at the same height than a small-framed person. You can estimate your frame size by wrapping your thumb and index finger around your wrist: if they overlap you have a small frame, if they touch it's medium, and if they don't meet it's large.

Should I aim for my exact ideal weight?

No — ideal weight formulas provide estimates, not prescriptions. A healthy weight exists within a range, not at a single number. Factors like muscle mass, body fat distribution, fitness level, and metabolic health matter more than a number on a scale. Use these results as a general guideline and focus on overall health markers like energy levels, strength, blood pressure, and body composition rather than chasing an exact target.

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