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Ideal Weight Calculator

Find your ideal weight range using multiple validated medical formulas.

?What is the Ideal Weight Calculator?

An ideal weight calculator estimates a healthy weight range for your height using multiple medically validated formulas — Robinson, Miller, Devine, and Hamwi — alongside the BMI-based healthy range (18.5–24.9). These classical formulas were originally developed for medication dosing (where body weight matters for dose calculation) but have been adopted widely as healthy-weight references. Showing several formulas together reveals that 'ideal weight' is a range, not a single number — different methods give slightly different values because they were developed with different populations and assumptions.

The Formula

Robinson (male): 52 kg + 1.9 kg × (height in inches − 60). Formulas differ slightly for females and between authors. BMI range: (18.5–24.9) × height²(m).

All four classic formulas start from a baseline weight at 5 ft (60 inches) height and add a fixed increment per inch above that baseline. The four authors (Robinson, Miller, Devine, Hamwi) derived slightly different baselines and increments from different study populations, so their numbers differ by a few kilograms. The BMI-based range covers all weights that yield BMI 18.5–24.9 for a given height, which is the widest-accepted modern definition of healthy-weight range.

Practical Examples

1

A 175 cm male: Robinson ≈ 70 kg, Miller ≈ 74 kg, Devine ≈ 72 kg, Hamwi ≈ 75 kg, BMI range 56.7–76.3 kg — a span of roughly 20 kg.

2

A 165 cm female: Robinson ≈ 57 kg, Devine ≈ 57 kg, Miller ≈ 60 kg, BMI range 50.4–67.8 kg — showing the importance of seeing a range.

3

A 180 cm male: Robinson ≈ 73.5 kg, Miller ≈ 77 kg, Hamwi ≈ 79 kg.

4

A 155 cm female: Robinson ≈ 53.5 kg, Devine ≈ 50 kg, BMI range 44.4–59.8 kg.

5

A tall 190 cm man has a wide healthy range of approximately 67 to 90 kg under BMI guidelines — different body frames naturally sit in different spots within that range.

6

A short 150 cm adult has a narrower range (42–56 kg) but same principle applies — frame size and muscle mass determine where within the range is 'right'.

Frequently Asked Questions

All four classic formulas are reasonable approximations. The BMI-based range (18.5–24.9) is the most commonly used medical reference today and acknowledges a band rather than a single point. Robinson and Devine are still standard for drug-dose calculations in hospitals. If the formulas disagree by a few kg, that disagreement itself is useful information: there is no single 'right' weight — there's a healthy range, and you can settle anywhere within it.