Wall Stud Calculator (Studs, Plates & Headers)

Enter the wall length and stud spacing, and how many corners and openings the wall has. The calculator counts the layout studs, adds the extra studs for corners and openings, and works out the plates and how many boards they take.

Wall studs calculator

How it works

Layout studs = wall length in inches ÷ spacing, rounded up, + 1 (the stud at the far end)
Extra studs = corners × studs per corner + openings × studs per opening
Studs to buy = (layout + extra) × (1 + waste %), rounded up
Plates = wall length × number of plates (a bottom plate and a double top plate is 3)

The IRC sets stud spacing by stud size, wall height and what the wall carries (Table R602.3(5)), and requires a double top plate on bearing walls unless the framing lines up (R602.3.2).

Worked example

A 20 ft wall at 16 in on center with a corner at each end and one window:

Wall length: 20 ft
Stud spacing: 16 in on center
Corners and wall intersections in this wall: 2
Extra studs per corner or intersection: 2
Doors and windows: 1
Extra studs per opening (king + jack): 4
Plates: Bottom plate + double top plate
Plate stock length: 16 ft
Extra studs for culls and waste: 10%

The calculator gives:

Studs to buy: 27
Layout studs: 16 (one every 16 in plus the end stud)
Extra for corners and openings: 8
Plates: 60 linear ft = 4 × 16 ft boards

240 in ÷ 16 = 15 spaces, so 16 layout studs. Two corners at 2 extra studs and one window with 2 king and 2 jack studs add 8, for 24 studs. With 10% for culls, buy 27. The plates are 60 ft of lumber, four 16 ft boards.

Notes and limits

The per-corner and per-opening figures are common framing practice, not code numbers. Change them to match how you frame (for example, 2-stud corners with drywall clips).
Cripples above headers and below sills, blocking and fire blocking are not counted. Offcuts often cover cripples.
Headers are sized from the IRC header span tables (R602.7) for the load; this tool does not size them.
The waste percentage covers crooked or split studs, and is your choice.

Frequently asked questions

How many studs for a 10 ft wall?

At 16 in on center, 9 layout studs (120 ÷ 16 = 7.5, rounded up to 8 spaces, plus 1). Add studs for corners and openings.

How do you calculate studs per linear foot?

A quick rule is one stud per foot of wall at 16 in on center. That covers layout studs plus typical extras for corners and openings. The calculator does it properly for your wall.

Is 24 in stud spacing allowed?

For many walls, yes. The IRC allows 24 in spacing for 2×4 and 2×6 studs in some situations, depending on wall height and how many floors the wall supports (Table R602.3(5)). Check the table or your plans.

Sources

International Code Council, 2021 International Residential Code, Section R602 Wood Wall Framing (stud spacing, Table R602.3(5); double top plates, R602.3.2)

Last reviewed: 25 September 2026. The calculation is covered by automated tests with known answers taken from the sources above. Found an error? Please let us know.