Ideal Weight Calculator
Find your ideal body weight using the Devine formula.
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Enter your height in centimetres and choose a gender, and this calculator estimates ideal body weight with the Devine formula. It shows the figure for the gender you selected, followed by the male and female results side by side so you can compare them.
The Devine formula
Men: 50 kg + 2.3 kg for every inch over 5 feet Women: 45.5 kg + 2.3 kg for every inch over 5 feet
The calculator converts your height to inches (cm ÷ 2.54), subtracts 60, and applies the formula.
Example: 170 cm
170 ÷ 2.54 = 66.93 inches, which is 6.93 inches over 5 feet. 2.3 × 6.93 = 15.94 kg, so the male result is 50 + 15.94 = 65.9 kg and the female result is 45.5 + 15.94 = 61.4 kg.
Example: 160 cm
160 cm is 62.99 inches, just under 3 inches over 5 feet, so the female result is 45.5 + 6.88 = 52.4 kg and the male result is 56.9 kg.
At 152.4 cm (exactly 5 feet) or below there are no inches to add, so the calculator returns the base values of 50 kg and 45.5 kg for any shorter height. The formula was never designed for people under 5 feet, so treat those results with extra caution.
Where the Devine formula came from
Dr B. J. Devine published it in 1974 to help doctors estimate medication doses, not to tell anyone what they should weigh. It stuck because it is simple, and hospitals still use close variants of it, for example to set ventilator volumes based on "predicted body weight". Other ideal-weight equations, such as Robinson, Miller and Hamwi, use slightly different numbers and can differ from Devine by a few kilograms at the same height.
Comparing the result with BMI
Ideal-weight formulas give a single number, while BMI gives a healthy range. For Asian Indians, national consensus guidelines treat a BMI of 23 or more as overweight, a lower cut-off than the international 25, because health risks rise at lower body weights in South Asian populations.
| Height | Devine (male / female) | Weight at BMI 23 |
|---|---|---|
| 160 cm | 56.9 / 52.4 kg | 58.9 kg |
| 170 cm | 65.9 / 61.4 kg | 66.5 kg |
If the Devine figure and your BMI range roughly agree, you have a sensible target zone. The BMI calculator gives the full range for your height.
What the formula leaves out
- Body composition: muscle is dense, so athletes often weigh more than their "ideal" while carrying little fat. The body fat calculator gives a better picture.
- Frame size and age: neither is part of the equation.
- Fat distribution: fat around the waist carries more health risk than the same weight elsewhere. Keeping your waist under half your height is a simple check many clinicians use.
Use the number as a rough reference point, not as medical advice or a goal you must hit.