What this calculator does
Adjusted body weight works out blends actual and ideal body weight, a middle-ground figure used for larger patients. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaAdjBW = IBW + 0.4 × (actual weight − IBW), IBW from the Robinson formula
The inputs explained
| Field | What to enter |
|---|---|
| Actual weight (kg) | A number, measured in kg. Starts at 100. |
| Height (cm) | A number, measured in cm. Starts at 175. |
| Sex | Choose from Male, Female. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with actual weight
Every other input is held at the calculator’s starting values while actual weight varies. Select any row to load that scenario into the calculator.