Adjusted Body Weight (AjBW) Calculator

You can also easily determine your Adjusted Body Weight (AjBW). It's the medical method used to estimate the optimal weight for accurate medicine dosing, food planning, and monitoring your metabolic health. This is a very handy calculator for health professionals, dietitians, and others concerned with obesity or muscular-weight differences.

Adjusted Body Weight Calculator
Enter your details to calculate your Ideal and Adjusted Body Weight using the Devine formula.

What is Adjusted Body Weight (AjBW)?

Adjusted Body Weight (AjBW) is a measure used to estimate a person's lean body mass, particularly for individuals who are overweight or obese. It "adjusts" their actual weight to account for the fact that fat tissue is less metabolically active than muscle tissue. This prevents overestimation when calculating calorie needs or medication dosages.

AjBW is not a weight loss goal. Instead, think of it as a "dosing weight"—a more accurate number for clinical calculations than either your actual or ideal weight.

The Formula for Adjusted Body Weight

The universally used AjBW formula used in hospitals is:

AjBW Formula

AjBW = IBW + 0.4 * (ABW - IBW)

Where: AjBW refers to Adjusted Body Weight, IBW means Ideal Body Weight, and ABW stands for Actual Body Weight. The adjustment factor (0.4) shows that 40% of your excess body weight falls in the metabolically active range.

Ideal Body Weight (IBW) Formula (Robinson Equation)

Men: 52 kg + (1.9 kg x (height in inches - 60))

Women: 49 kg + (1.7 kg x (height in inches - 60))

Example Calculation

Let's calculate AjBW for an individual who stands at a height of 5'11'' (180 cm) and weighs 90 kg.

IBW = 52 + 1.9 × (71 - 60) = 72.9 kg

AjBW = 72.9 + 0.4 × (90 - 72.9)

AjBW = 72.9 + 6.84 = 79.74 kg.

79.7 kg hai Adjusted Body Weight.

For nutritional calculations or drug dosing, this person should be rounded at about 79.7 kg and not at the 90 kg level.

How to use the Adjusted Body Weight Calculator

Our calculator usage is also swift and simple:

Step 01

Select your gender

Choose between female or male to apply the correct formula.

Step 02

Enter the height

Input your height in either inches or centimeters.

Step 03

Add actual body weight (ABW)

Provide your current, measured body weight.

Step 04

Click the 'Calculate' button

Get your Adjusted Body Weight (AjBW), Ideal Body Weight (IBW), and the difference in a matter of seconds.

Why Our Body Weight Adjustment Calculator Is Handy

Our calculator stands out because it's meant for professionals and lay citizens.

  • Accurate clinical formulas in compliance with Robinson and Bauer standards.
  • Direct calculation — no arithmetic required.
  • Dual results — shows both IBW and AjBW to make it clear.
  • Simple to use from any device — PC, tablete, nebo mobilní telefon.
  • Recommended healthcare — approved by health and nutrition specialists.

Benefits of Using Adjusted Body Weight

Promotes drug safety
Avoids overdosing and underdosing in the case of obese patients.
Personalized nutrition
Accommodates personalized nutrition: Calculates your true energy requirement.
Improves clinical accuracy
Visualises real metabolic mass instead of ABW.
Saves Time
Get immediate answers with no tedious calculations.
People-first method
Designed to inform, and not simply tally.

When You Need Body Weight in Adjustment

Use AjBW when:

  • The patient carries more than 20% over the ideal body weight.
  • You are conducting drug dosing (e.g., renal dosing, antibiotics, or chemotherapy).
  • You require the correct nutritional or calorie requirement for your weight management.

Limitations and Considerations

Avoid AjBW if:

  • The individual is an elite athlete with considerable muscle mass.
  • The person is pregnant or has swelling from fluid buildup.

AjBW presumes that 40% of the excess body weight at hand exists metabolically — this may not be the case for all. For people who are thin or athletes, use Lean Body Mass (LBM) or Fat-Free Mass Index (FFMI) instead. Always consult with a healthcare practitioner before using AjBW for medicine or health.

Frequently Asked Questions

Common questions and answers about our calculator