Ideal Weight Calculator — Healthy Weight Range by Height

This free ideal weight calculator estimates a healthy reference weight for your height and sex using established clinical formulas. It applies the Devine formula — the most cited equation, originally built for drug dosing — alongside the Robinson, Miller, and Hamwi formulas, which disagree by several kilograms because each was fitted to a different reference population. Treat the result as the centre of a healthy range, not a fixed target, since none accounts for frame size or muscle mass. All maths runs locally in your browser.

Devine formula
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BMI range (18.5–25)
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Robinson formula
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How is ideal weight calculated?

This calculator uses the Devine formula, one of the most widely cited methods in clinical settings. The formulas are:

Men: Ideal weight (kg) = 50 + 2.3 × (height in inches − 60)
Women: Ideal weight (kg) = 45.5 + 2.3 × (height in inches − 60)

For example, a man who is 175 cm (5'9") tall: 50 + 2.3 × (69 − 60) = 50 + 20.7 = 70.7 kg. Alternative formulas include Robinson (1983), Miller (1983), and Hamwi (1964) — all produce slightly different values. The calculator shows a healthy weight range (±10%) to reflect biological variation. No single number suits every individual: bone density, muscle mass, and body frame all affect what's genuinely healthy for you. Use ideal weight alongside BMI, waist circumference, and a doctor's assessment rather than as a standalone target.

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The formulas behind 'ideal weight'

There is no single ideal weight, so several formulas estimate a healthy reference from height and sex. The Devine formula (1974), originally built for drug dosing, is the most cited: 50 kg for men / 45.5 kg for women, plus 2.3 kg for each inch over 5 feet. The Robinson and Miller formulas adjust those constants slightly, and the Hamwi formula is common in US clinical settings.

Why they disagree

For a 5'10" man the formulas span roughly 68–75 kg — a 7 kg spread — because each was fitted to a different reference population decades ago. None accounts for frame size, muscle mass or age, so a powerlifter and a sedentary person of identical height share an 'ideal' that fits neither.

A better way to use it

Treat the result as the centre of a healthy range rather than a target. Combine it with body-fat percentage, waist measurement and how you feel and perform. A range of roughly ±10% around the formula output is a sensible, realistic band for most people.

⚠️ Common Mistakes to Avoid

Frequently asked questions

Which formula is best?

The Devine formula is the most widely used, but we provide results for several respected versions for comparison.

How does frame size affect it?

People with larger frames naturally carry more bone and muscle weight, shifting their 'ideal' range upward.

Related guides

Understanding TDEE →
Reviewed by the ToolsmithPro editorial team · Last updated June 2026. Every calculation and conversion runs entirely in your browser — your inputs are never uploaded, stored or shared. Formulas and methodology are documented on our about page; spot an error? tell us and we'll fix it.