Framing Lumber for a 20 ft Wall — 16" OC, 8 ft Studs
A 20-foot wall framed at 16 inches on center with 8-foot studs and 10% waste requires about 17 members.
How to use this tool
- Enter the total wall or floor span in feet.
- Set the on-center spacing (16 in or 24 in are most common).
- Enter the individual member length in feet.
- The result shows the number of members and total board linear footage to purchase.
Calculate how many 2×4 or 2×6 studs you need for a standard exterior or interior wall.
Frequently asked questions
- How many studs do I need for a wall?
- Divide the wall length by the stud spacing (in feet) and add 1 for the end stud. Add 10% for waste, corners, and headers. For a 20 ft wall at 16 in OC: (20 ÷ 1.33) + 1 = 16 studs, plus 10% waste = 18 studs.
- What is 16-inch OC spacing?
- OC stands for on-center — the distance from the center of one stud to the center of the next. 16-inch OC is the standard for exterior walls and load-bearing walls; 24-inch OC is used in non-load-bearing walls to save lumber.