Adjusted Body Weight Calculator
If you're trying to lose weight healthily and effectively, this adjusted body weight calculator is the tool for you. You may also find it handy if you're a professional dietitian — as using this calculator will allow you to save time calculating your patient's needs and thus make your work easier, quicker, and more efficient.
Read on to find the adjusted body weight formula, and learn how to calculate adjusted body weight on your own.
What is adjusted body weight?
Adjusted body weight (sometimes abbreviated to AjBW) is a measure used for calculating a person's nutritional needs, popular among dietitians when they are tasked with setting up a weight loss program. It is especially useful when the patient is overweight or obese. As adipose tissue is less metabolically active than lean tissue, using actual body weight for calculating one's energy requirements might result in some overestimations for people above their healthy BMI. Hence, it's often recommended to use AjBW instead.
How to use the adjusted body weight calculator?
To use our calculator, follow these instructions:

Provide the calculator with your sex.

Input your height.

Input your actual body weight.

The adjusted body weight calculator will use your sex, height and weight to figure out your ideal weight, which is a component of the adjusted body weight formula. Please note that there are several accepted equations used for calculating ideal weight based on slightly different scientific theories. However, the differences in results are practically negligible, so you shouldn't worry about them. You can read more about these theories at our ideal weight calculator. In this calculator, we use the Robinson formula.

The calculator will use the values you provided to calculate your AjBW and display it to you in the bottommost field.
How to calculate adjusted body weight?
Of course, our calculator will do the work for you quickly and effectively. Nevertheless, it may be worth knowing how to calculate adjusted body weight on your own — you never know when you will find yourself needing to give nutritional advice with no device to access our calculator at hand!
To calculate AjBW, the following adjusted body weight formula is used:
AjBW = IBW + 0.4 × (ABW  IBW)
where:
 AjBW is adjusted body weight;
 IBW is ideal body weight; and
 ABW is actual body weight.
Ideal body weight, according to Robinson's formula, is calculated as follows:
 For men:
52 kg + 1.9 kg per every inch over 5 feet
 For women:
49 kg + 1.7 kg per every inch over 5 feet
Calculating adjusted body weight — example
Let's say we want to determine the nutritional needs for a man who is 180 centimeters tall and weighs 90 kilograms. From the ideal weight formula, we get that his ideal weight would be 72.65 kilos. So we know that:
IBW = 72.65 kg
ABW = 90 kg
All we need to do is input these numbers into the adjusted body weight formula:
AjBW = 72.65kg + 0.4 × (90 kg  72.65 kg) = 72.65 kg + 0.4 × 17.35 kg = 72.65 kg + 6.94 kg = 79.59 kg
Now we know that when it comes to setting up a daily diet, this particular man should be treated as if he weighed 79.59 kilograms.
Limitations of the adjusted body weight calculator
It's essential to keep in mind that the adjusted body weight calculator is not appropriate in all situations. One should only use it when their excess weight comes from adipose tissue.
For example, many athletes weigh more than their appearance may suggest, and their simple BMIs are theoretically above the healthy level. Their "excess" weight comes from lean muscle tissue. In this case, AjBW does not apply. Also worth mentioning  for such individuals, it's recommended to use FFMI, rather than BMI. You can explore more by visiting our FFMI calculator and BMI calculator.
Another case where you should not rely on your adjusted body weight to calculate your needs is during pregnancy. If you're expecting a child and you're interested in how it might affect your weight, as well what a healthy diet is for you and your child, please refer to our pregnancy weight gain calculator.
FAQ
How do I calculate adjusted body weight?
To calculate adjusted body weight AjBW:

Use the adjusted body weight formula:
AjBW = IBW + 0.4 × (ABW  IBW)
IBW stands for ideal body weight, and ABW is the actual body weight.

Calculate the ideal body weight using Robinson's formula based on gender:

For men:
52 kg + 1.9 kg per every inch over 5 feet 
For women:
49 kg + 1.7 kg per every inch over 5 feet


Substitute the values for IBW and ABW in the AjBW formula to get the adjusted body weight.
What's the formula for adjusted body weight for obesity?
The formula for adjusted body weight for obesity is:
AjBW = IBW + 0.4 × (ABW  IBW)
Here, AjBW is the adjusted body weight, IBW is the ideal body weight, and ABW is the actual body weight.
This formula helps estimate the nutritional needs of overweight or obese patients more accurately than using their actual body weight.
When to use adjusted body weight?
Adjusted body weight is commonly used for patients who are overweight or obese, as it provides a more accurate estimation of their nutritional needs than using their actual body weight.
However, adjusted body weight may not be suitable for athletes who have a higher muscle mass, which can lead to theoretically higher BMIs. Additionally, it is not useful for calculating nutritional needs during pregnancy.
What's the ideal body weight for a 5 ft 5 in woman?
The ideal body weight is 57.5 kg when calculated using the ideal body weight using Robinson's formula for women:
IBW = 49 kg + 1.7 kg per every inch over 5 feet
In this case, there are 5 inches over the 5 feet:
IBW = 49 kg + 1.7 kg × 5
Simplifying this, we get:
IBW = 57.5 kg