Stud Spacing Calculator

Calculate stud spacing and the number of studs needed for wall framing

Wall Dimensions

Wall Length

feet + inches

Wall Height

Stud Spacing

On-Center Spacing

Stud Size & Wall Type

Stud Size

Wall Type

Openings (Doors & Windows)

Standard Doors (36")

Standard Windows (36")

Large Windows (60")

Double/Sliding Doors (72")

Each opening adds king studs, jack studs, cripple studs, and a header

How Stud Spacing Works

Wall studs are spaced at regular intervals measured from the center of one stud to the center of the next — this is called "on center" (OC). The spacing determines how many studs are needed and affects the structural capacity of the wall.

Stud Count Formula:

Number of Studs = (Wall Length in inches ÷ Spacing) + 1

The "+1" accounts for the starting stud at the beginning of the wall. Each wall also needs a top plate (usually doubled) and a bottom plate.

On-Center Spacing Compared

Spacing	Studs per 8' Wall	Use Case	Code Requirement
12" OC	9 studs	Heavy loads, tile backing, commercial	Exceeds most requirements
16" OC	7 studs	Load-bearing, exterior, most interior walls	Standard for most residential construction
24" OC	5 studs	Non-load-bearing interior partitions	Allowed for non-load-bearing with 2×4 or 2×6

Anatomy of a Framed Wall

Basic Wall Components

Bottom Plate (Sole Plate): Horizontal member on the floor; 1 piece the length of the wall
Top Plate: Horizontal member at the top; doubled (2 pieces) for load-bearing walls
King Studs: Full-height studs on each side of an opening
Common Studs: Regular studs spaced at OC intervals

Opening Components

Jack Studs (Trimmers): Shortened studs that support the header; nailed to king studs
Header: Horizontal beam above an opening; usually doubled 2× lumber
Cripple Studs: Short studs above a header or below a window sill
Sill Plate: Horizontal member at the bottom of a window opening

Corner Framing

Standard Corner: 3 studs to provide nailing surface for drywall on both sides
California Corner: Uses 2 studs + blocking; saves lumber and improves insulation
T-Intersection: Where an interior wall meets an exterior wall; needs backing studs

Header Sizes

Up to 4' span: Double 2×4 or 2×6
4' - 6' span: Double 2×6 or 2×8
6' - 8' span: Double 2×8 or 2×10
8' - 10' span: Double 2×10 or 2×12

Always verify with local building codes and an engineer for load-bearing walls.

Framing Tips

Always start layout from one end and mark every 16" (or chosen spacing) along the bottom plate
Pre-cut all common studs to the same length: wall height minus 3 plates (4-1/2" for single top, 6" for double top)
Crown all studs — sight down the narrow edge and face the crown (bow) the same direction
Use a speed square to mark layout lines perpendicular to the plate edge
Snap a chalk line on the floor to keep the bottom plate aligned before nailing
For 8' walls, use 92-5/8" pre-cut studs with a single bottom plate and double top plate
Stagger top plate joints at least 4' from bottom plate joints for rigidity
Add blocking (fire stops) at mid-height in walls taller than 10' per most codes

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Note: This calculator provides estimates for standard platform framing. Actual requirements depend on local building codes, load conditions, wind/seismic zones, and engineering specifications. Always consult your building code and a structural engineer for load-bearing walls. Add 10-15% extra lumber for waste, defects, and cutting errors.

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