AutoCAD Calculating Areas using Add and Subtract

By Martin Phelps

The following process has been requested by several delegates who have attended my AutoCAD Essentials course.

Note: -  the “Objects” in this example have been drawn as polylines as this can give better results. “Lines” and arcs can be used but the process differs slightly.

To access the “Area” command either type in the short cut “AA” and press enter, or in the “Utilities” panel of the “Home” tab of the “Ribbon”  menu expand the “Measure” tools and select “Area” as shown in Figure 1.

Figure 1.

Once the command has been selected, right click to display the menu and select “Add Area” as shown in Figure 2.

Figure 2.

The “Area” command is now in “Add” mode, right mouse click again to display the menu, this time select “Object” as shown in Figure 3.

Figure 3.

Select the outmost object, the selected object is now temporary filled in green as shown in Figure 4.

Figure 4.

The “Command Line” displays the “Area” of the selected object, more objects can be selected, and the accumulative “Area” of the selected “Objects” is displayed in the “Command line”.

To “Remove” the “Areas” of the internal shapes, press enter to confirm no more “Areas” are to be added. Right click to show the menu, this time select “Subtract Area”, right click again and select “Object”, select the “Objects” to remove their areas from the original, removed areas will be displayed with a red infill as shown in Figure 5.

Figure 5.

As the “Objects” are selected, the “Area” values are automatically subtracted from the original area and the updated value displayed in the command line. Pressing “CTRL+F2” will open AutoCAD’s text window displaying all the steps used as shown in Figure 6.

Figure 6.

If a record of this information is required, the text may be selected and copied to the clipboard, (CTRL+C) and paste from the clipboard (CTRL+V) into a word doc.

Cancelling the command removes the green and red infill colours.

As an alternative, instead of using the right click menu, the capital letter of each sub command may be typed followed by enter or select the subcommands from the “Command Line”.