Ideal body weight (IBW) formulas were created to dose medication, but they are also a handy reference point. This calculator shows the classic Devine formula alongside three alternatives.
How to use the Ideal Body Weight Calculator
- 1 Select your sex.
- 2 Enter your height in centimetres.
- 3 Compare the four formulas — the spread shows how approximate "ideal" weight is.
Formula
Devine (1974) Men: 50.0 kg + 2.3 kg per inch over 5 ft Women: 45.5 kg + 2.3 kg per inch over 5 ft Robinson: 52 / 49 kg + 1.9 / 1.7 kg per inch Miller: 56.2 / 53.1 kg + 1.41 / 1.36 kg per inch Hamwi: 48 / 45.5 kg + 2.7 / 2.2 kg per inch
Worked examples
Input: Male, 180 cm
Result: Devine: 75.0 kg
≈ 165 lb
Why are there several formulas?
Each formula was derived from different populations and for different purposes, so results differ by several kilograms. None accounts for frame size, muscle mass or age. Treat the range as a rough guide rather than a target.
Heights under 5 feet
All four formulas were designed for people at least 5 ft (152.4 cm) tall. Below that the formulas extrapolate and become less reliable.
This calculator provides general estimates for healthy adults and is not medical advice. Consult a doctor or registered dietitian before making significant changes to your diet or exercise.
Frequently asked questions
What is the Devine formula?
Men: 50 kg + 2.3 kg for each inch over 5 feet. Women: 45.5 kg + 2.3 kg for each inch over 5 feet.
Is ideal body weight the same as a healthy weight?
No. A healthy weight is a range (for example BMI 18.5–24.9); IBW is a single reference figure.
Why is it used in medicine?
Some drug doses and ventilator settings are based on ideal rather than actual body weight.
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