# What is my adjusted body weight?

Calculates adjusted body weight: Devine ideal body weight plus 0.4 of the weight above it, in kilograms and pounds, from sex, height, and weight.

- Page: https://www.acalculator.org/health/adjusted-body-weight-calculator
- JSON spec: https://www.acalculator.org/health/adjusted-body-weight-calculator.json
- Version: bfed9c75e342

## Default answer

Example with the default inputs (Sex Male, Height 5 ft 10 in, Weight 250 lb): The adjusted body weight is 89.2 kg (196.6 lb). The ideal body weight is 73 kg.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| sex | Sex | Sex at birth. The Devine formula has one line for men and one for women. |
| height | Height | Height without shoes, 5 ft (152.4 cm) or taller: the Devine formula starts at 5 ft. |
| weight | Weight | Actual body weight. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| adjusted | Adjusted body weight (kg) | Ideal body weight plus 0.4 of the difference between actual and ideal weight, in kilograms, to 1 decimal. |
| adjustedLb | Adjusted body weight (lb) | The adjusted body weight in pounds, to 1 decimal. |
| ideal | Ideal body weight (kg) | Devine ideal body weight in kilograms, to 1 decimal. |
| idealLb | Ideal body weight (lb) | Devine ideal body weight in pounds, to 1 decimal. |
| percentIdeal | Actual weight as % of ideal | Actual weight divided by ideal body weight, as a whole percent. |

## Method

Ideal body weight (Devine) = 50 kg (men) or 45.5 kg (women) + 2.3 kg per inch over 5 ft. Adjusted body weight = ideal + 0.4 × (actual − ideal).

## Assumptions

- Heights of 5 ft (152.4 cm) or more: the Devine formula is defined from 5 ft.
- The factor 0.4 is the one Bauer and others (1983) found for aminoglycosides; some drugs use other factors.
- Each weight is rounded to 1 decimal and the percent to a whole number, halves up.

## Worked examples

1. sex = male, height = 1.778, weight = 113.398093 gives ideal = 73, adjusted = 89.2, adjustedLb = 196.6, idealLb = 160.9, percentIdeal = 155%. Source: Devine 1974: 50 + 2.3 × 10 = 73 kg; Bauer 1983: 73 + 0.4 × (113.398 − 73) = 89.159 kg = 196.56 lb.
2. sex = female, height = 1.6256, weight = 90.718474 gives ideal = 54.7, adjusted = 69.1, adjustedLb = 152.4, percentIdeal = 166%.
3. sex = male, height = 1.8, weight = 100 gives ideal = 75, adjusted = 85, percentIdeal = 133%.
4. sex = female, height = 1.6, weight = 50 gives ideal = 52.4, adjusted = 51.4, percentIdeal = 95%.

## FAQ

### What is adjusted body weight?

Adjusted body weight (AdjBW or ABW) is a weight between ideal and actual body weight: the ideal weight plus 40% of the weight above it. Pharmacists use it for some drugs in people with obesity, because fat holds less of those drugs than muscle does.

### What is the adjusted body weight formula?

AdjBW = IBW + 0.4 × (actual weight − IBW). IBW is the Devine ideal body weight: 50 kg for men or 45.5 kg for women, plus 2.3 kg for each inch over 5 feet.

### Where does the 0.4 come from?

Bauer and others (1983) measured how aminoglycoside antibiotics spread in the body of people with morbid obesity and found that about 40% of the excess weight counted. The same factor is now used more widely, but some drugs use other factors, and the drug label or your pharmacist decides which weight to use.

### Why does the calculator need a height of 5 feet or more?

The Devine formula starts at 5 feet (60 inches) and adds weight for each inch above it. It has no published line for shorter adults.

## Sources

- Devine BJ. Gentamicin therapy. Drug Intell Clin Pharm. 1974;8(11):650-655. https://doi.org/10.1177/106002807400801104
- Bauer LA, Edwards WA, Dellinger EP, Simonowitz DA. Influence of weight on aminoglycoside pharmacokinetics in normal weight and morbidly obese patients. Eur J Clin Pharmacol. 1983;24(5):643-647. https://doi.org/10.1007/BF00542215
- National Institute of Standards and Technology. NIST Special Publication 811, Appendix B (1 lb = 0.45359237 kg, 1 in = 2.54 cm). https://www.nist.gov/pml/special-publication-811