IBW & ABW Calculator
Calculates Ideal Body Weight (Devine formula) and Adjusted Body Weight (ABW) for precise medication dosing in patients.
Biological Sex
Required for the Devine formula
Patient Height
Used to determine baseline Ideal Body Weight
cm
Actual Body Weight
Used to calculate Adjusted Body Weight if obese
kg
0.0
kg (IBW)
Analyzing…
Adjusted Body Weight (ABW): –
| Weight Type | Value (kg) | Typical Clinical Use Cases |
|---|---|---|
| Ideal Body Weight (IBW) | – | Acyclovir, Theophylline, standard maintenance IV fluids. |
| Adjusted Body Wt (ABW) | – | Aminoglycosides (if actual weight > IBW by 20-30%). |
| Actual Body Weight | – | Vancomycin, LMWH, Unfractionated Heparin. |
1
Patients under 5 feet (60 inches): The original Devine formula is approximations for ≥60 inches. This calculator applies the expert modification: subtracting 2 lbs (0.9 kg) for each inch below 60.
2
Fluid Overload: Actual body weight can be falsely elevated in patients with severe edema, ascites, or fluid overload. Clinical judgment is required.
3
Drug-Specific Protocols: Always consult specific pharmacy guidelines or drug monographs. Some institutions use 20% over IBW as the threshold to switch to ABW.