About the Adjusted Body Weight Calculator
Adjusted body weight (AdjBW, sometimes abbreviated ABW) is a weight estimate that sits between ideal body weight and actual body weight. It is used in clinical nutrition, pharmacy and critical care for people with obesity, because fat tissue is less metabolically active than lean tissue, so using actual weight overestimates needs while ideal weight underestimates them.
This calculator first works out ideal body weight (IBW) with the Devine formula — 50 kg for men or 45.5 kg for women plus 2.3 kg for each inch of height over 5 feet — and then adds 40% of the excess weight above IBW. You can switch the correction factor to 0.3 or 0.25 if your protocol uses a different value, and enter height and weight in metric or US units.
Adjusted weight is generally applied when actual weight is well above ideal (commonly more than 120–130% of IBW). The Devine formula was not designed for adults shorter than 5 feet or for children, and this tool does not provide any medication dose — always follow your local protocol or a pharmacist for dosing decisions.
With the default inputs, the adjusted body weight is 86.3 kg. Change any value above to recalculate instantly.
How to use the adjusted body weight calculator
- 1Choose metric or US units and select sex.
- 2Enter height and actual body weight.
- 3Keep the 0.4 correction factor unless your protocol specifies another.
- 4Read adjusted body weight alongside IBW and percent of IBW.
Formula and method
Ideal body weight comes from the Devine formula, originally published in 1974 and still the most widely used IBW equation in clinical practice. Height is converted to inches and each inch over 60 adds 2.3 kg to a base of 50 kg for men or 45.5 kg for women.
Adjusted body weight then adds a fixed fraction of the weight in excess of IBW — usually 40% (factor 0.4), reflecting the assumption that roughly 40% of excess weight in obesity is lean, metabolically active tissue. Some nutrition protocols use 25% or 30% instead. BMI is shown for context as weight in kilograms divided by height in metres squared.
- IBW
- Ideal body weight, kg (Devine)
- AdjBW
- Adjusted body weight, kg
- 0.4
- Correction factor (fraction of excess weight added)
Worked examples
Man, 175 cm and 110 kg
175 cm is 68.9 in, so IBW = 50 + 2.3 × 8.9 = 70.5 kg. The excess is 39.5 kg; adding 40% gives AdjBW = 70.5 + 15.8 = 86.3 kg.
Woman, 5 ft 4 in and 220 lb
IBW = 45.5 + 2.3 × 4 = 54.7 kg. 220 lb is 99.79 kg, an excess of 45.09 kg; 40% of that is 18.04 kg, so AdjBW ≈ 72.7 kg (160.4 lb).
Using a 0.25 factor
180 cm = 70.87 in, so IBW = 50 + 2.3 × 10.87 = 75.0 kg. With a 0.25 factor, AdjBW = 75.0 + 0.25 × 55.0 = 88.7 kg.
Frequently asked questions
What is the adjusted body weight formula?+
AdjBW = IBW + 0.4 × (actual body weight − IBW). Ideal body weight is usually calculated with the Devine formula: 50 kg (men) or 45.5 kg (women) plus 2.3 kg per inch over 5 feet.
When is adjusted body weight used?+
It is typically used for people whose actual weight is substantially above ideal — often more than 120–130% of IBW or a BMI of 30 or more — in contexts such as estimating energy and protein needs or as a dosing weight under specific protocols.
Why is the correction factor 0.4?+
Studies of body composition suggested that about 40% of excess weight in obesity is lean tissue that affects metabolism and drug distribution. The 0.4 factor became the convention, although some nutrition guidelines use 0.25 or 0.3.
Is adjusted body weight the same as lean body weight?+
No. Lean body weight estimates fat-free mass from height, weight and sex using different equations (such as Janmahasatian or Boer), while adjusted body weight is a simple blend of ideal and actual weight.
What if actual weight is below ideal body weight?+
Adjusted body weight is not meaningful in that case; clinicians normally use actual body weight instead. The calculator still shows the arithmetic result but flags it.
For healthcare professionals and education only. This calculator implements a published formula or score but is not a diagnosis and does not replace clinical judgment. Verify inputs and results against the original source before using them in patient care.