Calculating the volume of a parental drug required to be administered or added to an infusion:

• Volume required = (dose prescribed x volume of solution)/amount of drug in solution

This is the same as:

• Volume required = (what you want/what you’ve got) x what it’s in

Body surface area calculation:

• Body Surface Area (m 2) = √ (body weight (Kg) x Height (cm)) ÷ 3,600.