Adjusted Body Weight Calculator

Created by Maria Kluziak and Łucja Zaborowska, MD, PhD candidate
Reviewed by Bogna Szyk and Jack Bowater
Based on research by
Winter MA, Guhr KN, Berg GM. Impact of various body weights and serum creatinine concentrations on the bias and accuracy of the Cockcroft-Gault equation. Pharmacotherapy (July 2012)See 1 more source
Robinson JD, Lupkiewicz SM, Palenik L, Lopez LM, Ariet M. Determination of ideal body weight for drug dosage calculations. American Journal of Health-System Pharmacy (June 1983)
Last updated: Jun 05, 2023

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:

  1. Provide the calculator with your sex.

  2. Input your height.

  3. Input your actual body weight.

  4. 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.

  5. The calculator will use the values you provided to calculate your AjBW and display it to you in the bottom-most 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)


  • 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.


How do I calculate adjusted body weight?

To calculate adjusted body weight AjBW:

  1. 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.

  2. 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

  3. 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

Maria Kluziak and Łucja Zaborowska, MD, PhD candidate
Please provide the following data:
Actual body weight
Results of the calculations:
Ideal body weight
Adjusted body weight
As AjBW is used for calculating your nutritional needs, consider using it alongside our calorie calculator to get thorough information on your dietary requirements.
Check out 17 similar body measurements calculators 📏
A Body Shape Index (ABSI)BAIBody fat… 14 more
People also viewed…

Air force PT

The Air Force PT calculator allows you to estimate the number of points and performance level achieved during a physical fitness test.


The discount calculator uses a product's original price and discount percentage to find the final price and the amount you save.

Duke Activity Status Index (DASI)

The DASI calculator estimates the functional capacity of a patient. The tool is based on Duke Activity Status Index questionnaire and it can be used to get an estimate of a peak oxygen uptake and to evaluate patients with cardiovascular disease.

Flat vs. round Earth

Omni's not-flat Earth calculator helps you perform three experiments that prove the world is round.
Copyright by Omni Calculator sp. z o.o.
Privacy, Cookies & Terms of Service