Ideal Weight Formula Explained

This reference explains the Ideal Weight formula used by our free Ideal Weight Calculator. Use it to understand variables, units, and common mistakes before you calculate.

The formula

Reference ranges from Devine, Robinson, Miller, Hamwi, and BMI 18.5–24.9

Variables and units

• height — Standing height (in or cm)
• sex — Biological sex (formula differs) (male/female)

Worked example

Inputs: Male, 178 cm (70 in)

1. Devine formula (male): 50 + 2.3 × (70 − 60) = 50 + 23 = 73 kg
2. Robinson (male): 52 + 1.9 × (70 − 60) = 71 kg
3. BMI range 18.5–24.9 at 178 cm: 59–79 kg

Result: Ideal weight range roughly 59–79 kg (multiple formulas agree near 70–73 kg)

When to use this formula

Use this formula when you need a quick ideal weight estimate with values you already know. Our Ideal Weight Calculator applies the same relationship automatically so you can verify handwritten work.

Common mistakes

• Treating one formula as definitive (formulas vary by 5–10 kg)
• Ignoring frame size and muscle mass
• Using ideal weight for athletes with high lean mass

Frequently asked questions