Is that possible to copy the results of calculator in ZWCAD?

Yes it is possible to copy the result from the calculator. Select the result from the dialog box and let your cursor hover over it. Be careful and make sure your cursor is still hover over the calculator after selecting the result, because the dialog box is on the edge of the calculator, your cursor is easy to go out of the calculator area and make the copy to be unavailable. (Note: AutoCAD calculator works in the same way.)