The brand American Standard does not currently sell windows as of January 2016; however, some common dimensions in the United States for double-hung windows include widths of 24, 28, 32, 40 and 48 inches and heights of 44, 52, 54 and 62 inches. For picture windows, common dimensions include widths of 2, 3, 4, 5 and 8 feet and heights of 18, 24, 52, 54, 62 and 72 inches.
Sliding windows in the United Stated typically have widths of 36, 48, 60, 72 or 84 inches and heights of 24, 36, 48 or 60 inches.
The above sizes are the rough window sizes and are about 1/2 inch larger than the actual windows. For example, a double-hung window classed for a 24-by-44-inch rough opening would actually be 23.5 by 43.5 inches. The rough opening for a window should be made to be 24 by 44-inches; the additional 1/2 inch of space in each direction makes installation easier. Once the window is properly centered, the installer adds shims to keep it in place while attaching it to the rough opening.
Windows are often identified by a number describing the width and height of the rough opening in feet and inches. For example, a 2-foot-by-2.5-foot window would be identified by the number 2025.