Ideal Weight Calculator

Calculate Your Ideal Weight
Age (in years):
Gender: Male   Female
Height: feet inches

Based on the Devine formula,
your ideal weight is kgs

Based on the Hamwi formula,
your ideal weight is kgs


With awareness about the need for fitness growing in the society, a prominent factor that has come into play is, ‘how much should I weight for my height and age’? In other words, ‘what is my ideal body weight’?

To understand the reason behind this oft-asked question, let us first see what is ideal weight aka ideal body weight (IBW)? Ideal body weight is a clinical standard to determine how much should a person ‘ideally’ weight as per one’s age, height, and gender.

It is necessary to know your IBW because being underweight or overweight can lead to several health problems, chronic or otherwise. Please remember that your IBW should be calculated as per clinical parameters and not as per socially-perpetrated, irrational notions of beauty.

Health problems due to weight

A person’s weight keeps fluctuating till the age of 15. From then till around the age of 50, a person’s weight will increase by around 500 gms to 1 kg, keeping other factors like diet, physical activity etc. aside.

The thumb rule to see if you are gaining or losing weight beyond an ideal level, is to check whether the weight gain or loss per year is +5 or -5 kgs respectively from what your weight was at the age of 21.

Weight increase farther beyond the ideal level can make a person overweight or obese. Both these factors increase the chances of heart diseases, diabetes, musculoskeletal problems, sleep apnoea, infertility, and cancer amongst others.

Being underweight can lead to problems like chronic fatigue, osteoporosis, anemia, skin problems, and irregular periods amongst others.

How do ideal body weight calculators work?

Ideal body weight calculators also called IBW calculators or ideal weight calculators, take into account a person’s age, gender, and height and then apply certain time-tested formulae to arrive at what should be their ideal weight.

Why are these three factors important to arrive at one’s ideal weight?

• Well, a man’s and woman’s weight is different owing to differences in their muscle mass and bone density. The more the height of a person, the more will be their muscle mass and body fat.
• As for age, it is especially important because while weight fluctuates rapidly till the age of around 15-16, one also starts losing muscle mass faster after the age of 55-60, thus making it pertinent to factor in this aspect. Formulae for calculating IBWs usually consider gender and height more than age.

The two commonest formulae used are the Hamwi Formula and the Devine Formula.

  • According to GJ Hamwi Formula, ideal body weight is calculated for men as 48.0 kg + 2.7 kg per inch over 5 feet; and for women as 45.5 kg + 2.2 kg per inch over 5 feet.
  • According to BJ Devine’s formula, it is calculated for men as 50.0 kg + 2.3 kg per inch over 5 feet; and for women as 45.5 kg + 2.3 kg per inch over 5 feet.

BMI ratios and Waist-to-Hip ratios are other ways to estimate what should be a person’s ideal weight. But they have their limitations too. For instance, BMI does not differentiate between weight gained by fat deposition and weight due to muscle mass. Similarly, the waist-to-hip ratio might be complicated to analyze because one cannot say if the waist circumference is due to fats or muscle.

IBW calculators give a fair idea of what your optimum weight should be such that you can remain healthy.

If you find yourself overweight or underweight, it is best to approach trained professionals such as doctors, nutritionists, and fitness experts to ascertain the underlying causes behind your weight viz. dietary patterns, types of physical exercise you indulge in (or don’t indulge) in, stress levels, undetected health issues, and such others.

Taking their advice, one can embark on a weight correction journey in the proper manner.