Thread: How do I calculate the surface area of machined parts? i.e. rounded edges, holes, etc

I have 2 irregularly shaped parts that I am trying to calculate surface area as a prerequisite to determining coating weight. I figured water displacement would be the best way, but even then I'm not aware of what formula I would use. Suggestions?

Water displacement would measure volume of an object. I'd say surface area would best be determined by splitting up the object in calculable parts (Rounded corners = Parts of a sphere, cilinders, rectangles.) Calculating everything seperately then adding up the results.

I understand that displacement would measure volume, but I guess my idea was to measure the size of the displacement so to speak (in a cylinder shape), and do the math on that rather than break down the original piece into calculable shapes. My boss seems to remember being able to calculate this through density as well, but I can't say that I would know exactly how that calculation would work.

This may sound like a simple question, but say I chose to break the piece down into shapes. How do I calculate say... a rectangle with rounded edges as opposed to sharp ones?