Enter your height, sex, and actual body weight into the adjusted body weight calculator. The calculator will display both your ideal body weight and your adjusted body weight.

Adjusted Body Weight Calculator

Calculator
Quick Reference

Enter height, sex, and actual weight.

Drug dosing / renal Uses AdjBW = IBW + 0.40 × (Actual − IBW)
Nutrition estimate Uses adjusted weight = IBW + 0.25 × (Actual − IBW)
Results
Ideal Body Weight –
Actual Weight –
% of IBW –
120% of IBW –
Adjusted Body Weight –
Difference from IBW –
Recommendation –
Formula Used –
This calculator is for educational use. Specific medication and nutrition protocols may use actual, ideal, or adjusted body weight depending on the formula.

Quick Reference

IBW (Devine)

Male: 50 kg + 2.3 kg × inches over 60

Female: 45.5 kg + 2.3 kg × inches over 60

Drug dosing / renal AdjBW: IBW + 0.40 × (Actual − IBW)

Nutrition adjusted weight: IBW + 0.25 × (Actual − IBW)

  • %IBW = Actual ÷ IBW × 100
  • A common rule of thumb is to consider AdjBW when actual weight is above 120% of IBW.
  • Drug-specific dosing rules vary.
Medical safety note: This calculator is for educational use only and is not for dosing medications or making treatment decisions. Whether to use actual, ideal, or adjusted body weight depends on the specific drug/guideline and clinical factors (for example, kidney/liver function). The Devine IBW and ABW (0.4) formulas are not universally valid (including for children/adolescents, pregnancy, critical illness, edema/ascites, or amputations) unless a clinician directs you. The color categories describe only the % difference from an IBW estimate and are not a diagnosis of health status. For general “healthy weight” guidance, refer to public-health resources such as CDC BMI/healthy weight pages and discuss personal goals with a licensed clinician.

Adjusted Body Weight Formula

The following formula is used to calculate your adjusted body weight. 

ABW= IBW + 0.4 * (AW – IBW)
  • Where ABW is your adjusted body weight
  • IBW is your ideal body weight
  • AW is your actual weight.

In this case, your ideal body weight is determined by your height and sex using formulas like the ones below. 

Male: IBW = 50 kg + 2.3 kg * (Height – 60 in)
Female: IBW = 45.5 kg + 2.3 kg * (Height – 60 in)

Adjusted Body Weight Definition

Adjusted body weight (ABW) is an estimated weight used in some clinical and nutrition calculations—often in obesity—when using actual body weight may overestimate needs for certain formulas. ABW is calculated from ideal body weight (IBW) and actual body weight; it does not measure body composition and does not diagnose health.

In practice, whether ABW is appropriate depends on the specific calculation and guideline being used.

Some healthcare teams may use ABW as one possible input for selected weight-based calculations, but the “right” weight to use can vary by drug, indication, and patient factors.

ABW can be useful because using actual body weight may not be appropriate for every formula in every context. However, ABW is still only an estimate and should be interpreted cautiously.

For example, two people can have the same actual body weight with very different body composition (fat mass vs. muscle mass). The ABW formula does not distinguish between these differences—it simply adjusts a Devine-based IBW toward actual weight by a fixed factor.

How to calculate adjusted body weight?

How to calculate adjusted body weight

  1. First, measure your height

    This value will be used in determining your ideal body weight.

  2. Next, measure your weight

    Using an accurate scale, measure your actual body weight.

  3. Calculate your ideal body weight

    Calculate your ideal body weight using one of the two formulas above.

  4. Calculate your adjusted body weight

    Using your ideal weight and actual weight, calculate your adjusted body weight.

FAQ

What is adjusted body weight?

Adjusted body weight is a metric used for determining a person’s nutritional requirements. It’s often used when a person’s actual body weight is far out of line with their ideal body weight.

What is an ideal body weight?

Ideal body weight is an estimate used in some medical formulas. It is not a diagnostic target and does not by itself determine health. Healthy weight depends on multiple factors; consider discussing goals with a clinician.

Calculator Change Log:

  • 6/13/25 – Added a quick reference tab, interpretation field, and excess weight field for more in-depth understand of adjusted body weight and ideal body weight.