Use drop-down list to convert column from Lb to Kg
What I'd like to do is use a drop-down list that consists of two values, kg or lb, and when one is selected, have it run a calculation to convert a column (or multiple columns) from one to the other. The column is now in pounds. If the drop down is at "lb", then do nothing and use the value as-is. If it changes to "kg", then multiply each value in the column by 0.45359237.
It sounds easy in my head but I'm sure that it isn't. Any help would be appreciated.