IBW Estimated ideal body weight in (kg) Males: IBW = 50 kg +
2.3 kg for each inch over 5 feet. Females: IBW = 45.5 kg + 2.3 kg for each
inch over 5 feet.

ABW Estimated adjusted body weight (kg) If the actual
body weight is greater than 30% of the calculated IBW, calculate the
adjusted body weight (ABW): ABW = IBW + 0.4(actual weight - IBW)

The IBW and ABW are used to calculate medication dosages when the patient is
obese.

This formula only applies to persons 60 inches (152 cm) or taller.
If calculating by hand use formula as shown (inches & kilograms).
Formulas referenced from GlobalRPH.

Examples

Example 1

Calculate the ideal body weight (IBW) of a man who is 64 inches tall and
weighs 70 kilograms. If this man is obese (> IBW + 30%), calculate the
adjusted body weight.

To solve the example using the calculator, select the radio button
for male. Next, enter the height (inches) and weight (kilograms):

weight = 70 kg height = 64 inches IBW = 59.2

Or solve using formula:

IBW = 50 kg + 2.3 x each inch over 5 feet (60inches) IBW = 50
kg + 2.3 x 4 inches IBW = 50 kg + 9.2 IBW = 59.2 kg

The man's actual weight is less than IBW + 30% so it is not
necessary to calculate the adjusted body weight (ABW).

Example 2

Calculate the ideal body weight (IBW) of a woman who is 64 inches
tall and weighs 80 kilograms. If this woman is obese (> IBW + 30%),
calculate the adjusted body weight.

To solve the example using the calculator, select the radio button
for female. Next, enter the height (inches) and weight (kilograms):

weight = 80 kg height = 64 inches IBW = 54.7

Or solve using formula:

IBW = 45.5 kg + 2.3 x each inch over 5 feet (60inches) IBW =
45.5 kg + 2.3 x 4 inches IBW = 45.5 kg + 9.2 IBW = 54.7 kg

The woman's actual weight is greater than the IBW + 30%, so
calculate the ABW:

ABW = 54.7 kg + 0.4( 80kg - 54.7 kg) ABW = 54.7 kg + 0.4( 25.3
kg ) ABW = 54.7 kg + 10.1kg ABW = 64.8 kg

DISCLAIMERThis page is intended for educational purposes. It is not intended for clinical applications. The author cannot be responsible for misuse or misapplication of the material on this page.