Slide 1
Calculation IBW and ABW
Estimated ideal body weight in ( 18 YR and above)(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.
ABWEstimated 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. REFRANCE : ASHP's popular book by McPherson, now with 2011
Update!
2Conversion 1 foot is equal to 12 inches 1 inch is equal to 2.54
cm1 foot is equal to 30.48 cm5 foot is equal to 152.4 cm1 Ib is
equal to 2.2 kg
Examples
Example 1Calculate 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.
The man's actual weight is less than IBW + 30% so it is not
necessary to calculate the adjusted body weight (ABW).
IBW = 50 kg + 2.3 x each inch over 5 feet (60inches)IBW = 50 kg
+ 2.3 x 4 inchesIBW = 50 kg + 9.2IBW = 59.2 kgEXAMPLEExample
2Calculate 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.The woman's actual weight
is greater than the IBW + 30%, so calculate the ABW:
IBW = 45.5 kg + 2.3 x each inch over 5 feet (60inches)IBW = 45.5
kg + 2.3 x 4 inchesIBW = 45.5 kg + 9.2IBW = 54.7 kg
ABW = 54.7 kg + 0.4( 80kg - 54.7 kg)ABW = 54.7 kg + 0.4( 25.3 kg
)ABW = 54.7 kg + 10.1kgABW = 64.8 kg
BMI
If, for example, you are 80 inches tall and you weight 160
pounds, the formula would look like this: 160/6400703=17.57 or like
this: 160(703)/6400=17.57. In both cases, the results, your BMI,
are the same: 17.57.
6Interpret BMIunder 18.5 you are considered underweight from
18.5 to 24.9 are normalfrom 25.0 to 29.9 are overweight from 30.0
to 39.9 are obeseBMI over 40.0 is considered morbidly obese.
Body Surface Area (BSA)The Mosteller formulaIn metric :
or in inches and pounds:
Thanks
