How many studs do I need for a 10 ft wall?

At 16" on center, a 10 ft wall has 9 layout studs; at 24" it has 6. Add studs for corners, intersections and the king and jack studs at any doors or windows.

How many studs per foot of wall?

Layout alone is 0.75 studs per foot at 16" on center, plus one for the end. Once corners, openings and waste are added, real walls come out higher: the 24 ft example on this page needs 32 studs, about 1.3 per foot.

What length studs do I need for an 8 ft wall?

Precut 92-5/8" studs. With a bottom plate and a double top plate they frame a 97-1/8" wall. For 9 ft walls use 104-5/8", and for 10 ft walls 116-5/8".

Can I frame walls 24 inches on center?

Under IRC Table R602.3(5), 2x4 studs can be 24" on center when the wall supports only a roof and ceiling, and 2x6 studs can be 24" with one floor above. A 2x4 wall under a floor must be 16" on center.

What are king, jack and cripple studs?

King studs run full height beside an opening. Jack studs, also called trimmers, sit inside the kings and hold up the header. Cripples are the short studs above the header and below a window sill that keep the layout going.

Wall Stud Calculator

Enter the wall length, height and stud spacing, then add corners, intersections, doors and windows to get a full stud count, the plates to order and a check against the IRC spacing table.

By ChiselJobs Team · Updated October 13, 2026

The Wall

Wall Length (ft)Wall HeightStud Spacing (in on center)Stud SizeWall SupportsCornersExtra Studs per CornerWall IntersectionsExtra Studs per Intersection

Doors and Windows

King Studs per SideJack Studs per Side

Opening 1Rough Width (in)

The number of king and jack studs at each opening depends on the header span and loads; the IRC header tables set it.

Material List

Plate Stock LengthWaste (%)

Studs to Buy

25 at 92-5/8"

Includes 2 jack studs and 3 for waste

Layout Studs

Removed for Openings

Corners and Intersections

King Studs

Cripples (from offcuts)

Plates (1 bottom, 2 top)

60 ft, 4 x 16 ft

Spacing 16" (maximum 24" for 2x4 studs supporting roof and ceiling only, IRC Table R602.3(5))
Wall height 97-1/8" (exterior bearing studs over 10 ft need engineering)

Plate count is the straight length of three plates. Top plate splices must lap at least 24", so add stock for laps at splices, corners and intersections. Utility grade 2x4 studs are limited to 16" on center.

How to Count Wall Studs

Start with the layout studs: divide the wall length in inches by the stud spacing, round up, and add one for the stud at the far end. A 20 ft wall at 16" on center has 15 spaces and 16 studs.

Then adjust for everything that is not a plain stud on layout. Corners and wall intersections need extra studs for backing and nailing. Each door or window replaces the layout studs inside it with king studs at each side, jack studs under the header and short cripple studs above the header (and below the sill on a window).

Finally, count the plates (one bottom plate and a double top plate on a bearing wall) and add a waste allowance for crooked or split studs.

Corners, Openings and Plates

The calculator counts each piece separately so you can match it to how your crew frames.

Corners: a traditional three-stud corner adds two studs to the layout; a two-stud or California corner adds fewer. Set the extra studs per corner to match your detail.
Intersections: where a partition meets a wall, extra studs or blocking give the partition something to nail to. The calculator defaults to two extra studs; set fewer if you use blocking.
King studs run full height beside an opening. Jack studs (trimmers) are cut short and carry the header. The IRC header tables set how many of each a given header needs.
Cripples are the short studs above a header and below a window sill, usually cut from offcuts.
Plates: one bottom plate plus a double top plate whose splices lap at least 24".

Stud Formulas

L is the wall length in inches and S is the stud spacing in inches.

Layout studs

N = round up (L ÷ S) + 1

Studs replaced by an opening

n = round down (W ÷ S)

Full-length studs

Full = N − Σn + corners + intersections + kings

Studs to buy

Total = (Full + jacks) × (1 + waste)

Plates

Plate length = 3 × wall length

Stud length

Stud = wall height − 3 × 1-1/2"

L: Wall length in inches
S: Stud spacing on center in inches
W: Rough opening width in inches
N: Studs on layout, including both ends

Waste is rounded up to whole studs. Cripples are listed separately because most come from offcuts.

Worked Example: 24 ft Exterior Wall

A 24 ft, 8 ft tall exterior wall at 16" on center with a corner at each end, one partition intersection and two 36" windows. One king and one jack per side, 10% waste.

Layout: 288 ÷ 16 = 18 spaces, so 19 studs.
Windows: each 36" opening replaces 2 layout studs, 4 in all, leaving 15.
Corners and intersection: 2 × 2 + 1 × 2 = 6 studs. Kings: 4. Full-length studs: 15 + 6 + 4 = 25.
Jacks: 4. Waste: 10% of 29 is 2.9, so 3 studs. Total: 32 precut studs at 92-5/8".
Cripples above and below two windows: 8, from offcuts. Plates: 72 ft, or 5 pieces of 16 ft stock.

Result: order 32 precut studs and 5 sixteen-footers for plates, plus stock for the top plate laps.

Worked Example: 12 ft Partition With a Door

A 12 ft interior partition at 16" on center with a 38" rough opening for a door and no waste allowance.

Layout: 144 ÷ 16 = 9 spaces, so 10 studs.
The 38" opening replaces 2 studs: 8 left. Kings: 2. Full-length studs: 10.
Jacks: 2. Cripples above the header: 2.

Result: 12 studs plus 36 ft of plate.

Worked Example: Same Wall at 24" on Center

The 24 ft exterior wall from the first example, framed at 24" on center.

Layout: 288 ÷ 24 = 12 spaces, so 13 studs. Each window replaces 1, leaving 11.
With 6 for corners, 4 kings, 4 jacks and 3 for waste: 28 studs, 4 fewer than at 16".

Result: 24" spacing is allowed for 2x4 walls carrying only a roof and ceiling, but not for 2x4 walls under a floor, which must be 16" on center.

Layout Studs by Wall Length

Studs on layout, including both ends, before corners, intersections and openings.

Calculated: wall length ÷ spacing, rounded up, plus one.
Wall length	12" o.c.	16" o.c.	24" o.c.
4 ft	5	4	3
6 ft	7	6	4
8 ft	9	7	5
10 ft	11	9	6
12 ft	13	10	7
14 ft	15	12	8
16 ft	17	13	9
20 ft	21	16	11
24 ft	25	19	13
30 ft	31	24	16
36 ft	37	28	19
40 ft	41	31	21

Precut Stud Lengths

Precut studs are sized for a single bottom plate and a double top plate.

Framed height = precut stud + three 1-1/2" plates.
Wall	Precut stud	Framed height with 3 plates
8 ft	92-5/8"	97-1/8"
9 ft	104-5/8"	109-1/8"
10 ft	116-5/8"	121-1/8"

Field Tips

Practical advice from JLC’s wall framing field guide and Fine Homebuilding, checked against the IRC.

1
Precut studs leave room for drywall
A 92-5/8" precut stud with three plates frames a 97-1/8" wall. That fits the ceiling drywall plus two 4 ft wall sheets and still leaves a small gap at the floor for a dipping ceiling or a hump in the floor.
2
Lap the top plates
Lap double top plates at corners and intersections and stagger the splices. Code requires at least 24" of overlap; 48" gives the wall more racking resistance.
3
Check the grade before going to 24"
2x4 studs can be 24" on center only when the wall carries just a roof and ceiling, and only in Standard grade or better. Utility grade 2x4s are limited to 16".
4
Mind notches and holes
In a bearing stud under 10 ft, notches should not exceed 25% of the stud depth, and bored holes should not exceed 40% of the width and stay at least 5/8" from the edge. Never notch and drill across from each other.
5
Tall walls need engineering
Studs in exterior bearing walls over 10 ft tall, 2x4 or 2x6, should be engineered. The usual fixes are closer spacing, wider studs, doubled studs or engineered lumber studs.

Sources: JLC Field Guide: Wall framing, JLC: Precut stud lengths, Fine Homebuilding: Do precut studs make sense?