How many studs do I need for a 20-foot wall?

A 20-foot wall at 16" OC spacing needs 16 studs (20 / 1.333 + 1 = 16). Add studs for any corners (3 each), doors (4 each), and windows (6 each). You will also need 60 linear feet of plate material (3 plates x 20 feet).

Why is 16 inches on center the standard?

The 16" OC standard works perfectly with standard 4' x 8' sheathing and drywall -- the edges always land on a stud (48" / 16" = 3 spaces). It also provides adequate support for most residential loads per building codes.

When can I use 24-inch spacing?

24" OC spacing is allowed for non-load-bearing interior partition walls in most building codes. Some advanced framing techniques use 24" OC for exterior walls with 2x6 studs, but check your local code first.

What length studs do I buy for an 8-foot wall?

For standard 8-foot walls, buy precut 92-5/8" studs (sometimes labeled as 8-foot precut). These are shorter than a full 96" (8 feet) to account for the three plates: one bottom plate and a double top plate, each 1-1/2" thick (4-1/2" total).

Stud Spacing Calculator

Getting the stud count right before you start framing saves trips to the lumber yard and keeps your project on schedule. This calculator figures out the total number of studs based on your wall length, spacing, plus extras for corners, intersections, doors, and windows.

Basic Stud Count Formula

The starting formula is simple: Studs = (Wall Length / Spacing) + 1. The extra stud accounts for the one at the very start of the wall. From there, you add studs for special framing situations.

Standard Stud Spacing Options

Spacing	Use	Notes
16" OC	Standard bearing walls	Required by most codes for load-bearing walls
24" OC	Non-bearing walls	Saves material on interior partition walls
12" OC	Heavy load areas	Used under point loads or in high-wind zones

"OC" means "on center" -- measured from the center of one stud to the center of the next.

Extra Studs for Openings

Doors and windows need additional framing members:

Each door requires:

2 king studs (full-height studs on each side)
2 jack studs (shorter studs that support the header)
1 header (sized to span -- see our header size calculator)

Each window requires:

2 king studs
2 jack studs
2 cripple studs (short studs above and below the window)
1 header and 1 sill plate

Corner and Intersection Framing

L-corners need 3 studs to provide nailing surfaces for drywall on both walls. The most common method uses two studs with blocking or a third stud turned sideways.

T-intersections (where a partition wall meets an exterior wall) need 3 extra studs or 2 studs with ladder blocking.

Plate Material

Every wall needs 3 plates running the full length: 1 bottom plate (sole plate) and 2 top plates (double top plate). The double top plate is required for load-bearing walls and ties corners and intersections together.