Frequent contributor Alan Thompson is back this month with a nice little AutoCAD routine that's designed to be loaded at startup time, so insert this code into your ACADDOC.LSP file. Once loaded, this program creates a reactor that detects when you select one or more entities with a length and/or area. When these objects are selected, the length and area properties are displayed in the AutoCAD status bar. You do not have to do anything other than select the entity!
There are also two optional commands that go with this routine. Once you have queried an object, type in AreaClip to copy the last set of values to the system clipboard. From here, you can paste this data into any other application (such as Notepad, for example). The other command is AreaInfo, which will copy the last set of values to a CSV file and open it. Typically the file will open in your spreadsheet application (such as Microsoft Excel).
When using this routine, note that self-intersecting polylines generate a different area value than what is generated by AutoCAD, so use this with caution on these types of entities. Also, for a collection of multiple entities that seemingly form a closed area, the area reported is the sum of each entity, not the area contained within them. Always used a closed polyline or spline in this case.