Last updated: Nov 8, 2023
How much should I weigh for my height and gender?
The ideal body weight calculator uses several different formulae to find your ideal weight. Find out your ideal weight range
Healthy body weight calculator (IBW)The ideal body weight calculator uses several different formulae to find your ideal weight. Find out your ideal weight range
Calculating a person's ideal weight involves using various formulas and methods, such as the Robinson, Devine, Hamwi, and BMI formulas. These methods provide estimates based on an individual's height, gender, and in some cases, frame size. However, it's important to note that these formulas are approximations and do not account for all factors that determine a person's overall health and well-being.
Body Mass Index (BMI): BMI is one of the most commonly used methods for estimating ideal weight. It is a simple formula that relates a person's weight to their height. The BMI formula is:
BMI = weight (kg) / (height (m) * height (m))
The resulting BMI value can be used to categorize individuals into different weight categories, such as underweight, normal weight, overweight, and obese. Here are the BMI categories and their corresponding values:
For example, if a person's height is 1.75 meters and their weight is 70 kilograms, their BMI can be calculated as follows:
BMI = 70 kg / (1.75 m * 1.75 m) = 22.86
In this case, the individual falls into the "Normal weight" category.
However, BMI has limitations because it does not account for variations in body composition. It doesn't distinguish between muscle and fat, and it doesn't consider factors like age, gender, or frame size.
Robinson Formula: The Robinson formula is an alternative method to estimate ideal body weight. It is based on a person's height and gender. The formula is different for men and women:
To use the Robinson formula, you would convert the person's height from feet and inches to inches and then apply the formula to calculate the ideal body weight. For instance, if a woman is 5 feet 6 inches tall:
Ideal body weight = 49 kg + (1.7 kg * 6 inches) = 49 kg + 10.2 kg = 59.2 kg
This method takes into account height and gender but does not consider frame size or other factors like body composition.
Devine Formula: The Devine formula is similar to the Robinson formula but uses a slightly different approach to calculate ideal body weight based on height. It's also separate for men and women:
Using the Devine formula, you would apply the appropriate formula based on the person's gender and height. For instance, if a man is 6 feet tall:
Ideal body weight = 50 kg + (2.3 kg * 12 inches) = 50 kg + 27.6 kg = 77.6 kg
Like the Robinson formula, the Devine formula considers only height and gender but does not account for frame size or body composition.
Hamwi Formula: The Hamwi formula is often used to estimate ideal body weight for adults, and it takes into account height and frame size. There are separate formulas for men and women:
To use the Hamwi formula, you would calculate the initial ideal body weight based on height and then apply the appropriate frame size adjustment. For example, if a woman is 5 feet 8 inches tall with a medium frame:
Initial ideal body weight = 45.5 kg + (2.2 kg * 8 inches) = 45.5 kg + 17.6 kg = 63.1 kg
Then, adjust the result for a medium frame:
Ideal body weight with medium frame = 63.1 kg
The Hamwi formula takes into account both height and frame size, making it more personalized compared to some other methods.
It's important to emphasize that these formulas provide rough estimates of ideal body weight, and individual variations can significantly affect what is truly ideal for a person. Factors like muscle mass, age, overall health, and personal goals are essential considerations when assessing a person's weight and health. Additionally, consulting with healthcare professionals, such as doctors or registered dietitians, can provide a more comprehensive and tailored approach to determining an individual's ideal weight and overall well-being.