Translations:ExpressionScript Engine - Quick start guide/31/en
From LimeSurvey Manual
In this case, weightkg is {if(weightunits == "kg", weight, weight * 0.453592)}. This "if()" function means that if the subject enters the weight using kilograms, use that value, otherwise multiply the entered value (pounds is the alternative) by 0.453592 to convert it to kilograms. The heightm variable uses a similar approach to compute the person's height in meters (height in cms/100), even if he has entered his height in inches (1 meter=3.28084 inches).