Framing Spacing refers to the intervals that studs are located at within the wall framing. The Effective R tool lists stud spacing options of 8 inches (203 mm), 12 inches (305 mm), 16 inches (406 mm), 19.2 inches (488 mm), and 24 inches (610 mm) on centre. The most common spacing for studs in wall framing is 16 inches (406 mm) or 24 inches (610 mm) on centre. Stud spacing greater than 24 inches (610 mm). typically requires professional design and is not used in the Effective R Tool.