GreatCalc
العربية

Ideal Weight Calculator

Estimate your ideal weight with four classic formulas (Devine, Robinson, Miller, Hamwi) and the healthy BMI range.

Enter the values to see the result here.

For general information, not medical advice. Talk to a doctor before making health decisions.

Formula

With height in inches and o=height−60o = \text{height} - 60 (inches over five feet), the weight in kg for men is:

Devine=50+2.3 oRobinson=52+1.9 oMiller=56.2+1.41 oHamwi=48+2.7 o\begin{aligned} \text{Devine} &= 50 + 2.3\,o \\ \text{Robinson} &= 52 + 1.9\,o \\ \text{Miller} &= 56.2 + 1.41\,o \\ \text{Hamwi} &= 48 + 2.7\,o \end{aligned}

For women the constants are 45.5 + 2.3o, 49 + 1.7o, 53.1 + 1.36o and 45.5 + 2.2o. The BMI band for height hh in metres is 18.5 h218.5\,h^2 to 24.9 h224.9\,h^2.

Worked example

A man 175 cm tall.

  • Inches: 175/2.54=68.9175 / 2.54 = 68.9, so o=8.9o = 8.9.
  • Devine: 50+2.3×8.9=70.550 + 2.3 \times 8.9 = 70.5 kg. Robinson: 68.968.9 kg. Miller: 68.768.7 kg. Hamwi: 72.072.0 kg.
  • Average: about 70.070.0 kg.
  • BMI band at 1.75 m: 56.756.7 to 76.376.3 kg, which comfortably contains all four results.

Common mistakes

  • Using the formula weight as a goal for a muscular or very broad-framed person.
  • Applying a formula to someone under 5 feet and trusting the extrapolation.
  • Comparing results across tools that use different formulas without noticing.
  • Expecting children or teenagers to fit these adult formulas.

Frequently asked questions

Why do the four formulas give different answers?

Each was fitted to different data. Devine and Hamwi were written for drug dosing and sit slightly higher; Miller gives the lowest values at average heights. A spread of 3 to 4 kg is normal, which is why the tool shows all four and their average.

Is the ideal weight the same as the healthy BMI range?

No. The formulas give one number from height and sex alone. The BMI range (18.5 to 24.9) gives a band, which is more honest because healthy weight depends on frame, muscle and age.

Do these formulas work for short people?

They were built for heights above 5 feet (152 cm). Below that the formula extrapolates in a straight line and can look too low, so lean on the BMI range.

Should I aim for exactly this weight?

No. Use it as a reference point. Waist size, fitness, blood pressure and blood tests tell you more about health than a single target weight.

Related calculators