Adjusted Body Weight Calculator
Use this tool to estimate Adjusted Body Weight (AdjBW) from sex, height, actual weight, and a correction factor.
Educational use only. Clinical decisions should be made by a qualified healthcare professional.
What is adjusted body weight?
Adjusted body weight (AdjBW) is an estimated weight used in some healthcare settings when actual body weight may overestimate dosing or calorie needs. It sits between Ideal Body Weight (IBW) and Actual Body Weight (ABW) by applying a correction factor.
A common use case is medication dosing and nutrition planning in individuals with higher body weight, especially when clinicians want to avoid underdosing based on IBW alone or overdosing based on actual body weight alone.
The formula
Adjusted Body Weight (kg) = IBW + CF × (Actual Weight − IBW)
Where:
- IBW = Ideal Body Weight
- CF = correction factor (often 0.4, but may vary by protocol)
- Actual Weight = measured body weight
How IBW is estimated in this calculator
This calculator uses the Devine equations:
- Male: IBW = 50 + 2.3 × (height in inches − 60)
- Female: IBW = 45.5 + 2.3 × (height in inches − 60)
Height is converted internally as needed. Output is shown in both kilograms and pounds.
When clinicians may use adjusted body weight
- Estimating drug doses for selected medications
- Nutrition support calculations in obesity
- Situations where ABW is likely to overestimate pharmacokinetic needs
Importantly, not all medications or nutrition equations use AdjBW. Some use ABW, IBW, lean body mass, body surface area, or eGFR-based approaches. Always follow condition-specific and medication-specific guidance.
Step-by-step example
Example inputs
- Sex: Male
- Height: 70 inches (5'10")
- Actual weight: 240 lb
- Correction factor: 0.4
Calculation
1) IBW = 50 + 2.3 × (70 − 60) = 73 kg
2) Convert actual weight: 240 lb ≈ 108.9 kg
3) AdjBW = 73 + 0.4 × (108.9 − 73) = 87.4 kg
So the adjusted body weight estimate is approximately 87.4 kg (about 192.7 lb).
Choosing a correction factor
The default correction factor in many references is 0.4, but you may also see values like 0.25 or 0.5 depending on institutional policy or specific use case. This calculator allows custom values from 0 to 1.
- Lower CF keeps AdjBW closer to IBW
- Higher CF moves AdjBW closer to actual body weight
Limitations and safety notes
- AdjBW is an estimate, not a direct measurement of lean mass or metabolic demand.
- Different populations may require different formulas.
- Sex-based equations do not reflect all body compositions and clinical contexts.
- For pediatrics, pregnancy, critical illness, and renal/hepatic dosing, specialized methods may be needed.
This page is educational and should not replace professional medical judgment.
Quick FAQ
Is adjusted body weight the same as ideal body weight?
No. AdjBW is calculated from IBW plus a fraction of excess actual weight.
Should everyone use adjusted body weight?
No. It is used only in specific contexts where protocol or evidence supports it.
Why does my result include both kg and lb?
Many clinical references use kg, while patients and some systems use lb. Showing both reduces conversion errors.