Free calculator
Stud calculator: studs, plates, headers and sheathing
List the walls, set the spacing and count the corners, tees and openings, and get a lumber list: studs by precut length, plates on the stock length you buy, header stock and sheathing. A 20-ft wall at 16 inches on center with two corners and two openings needs 27 studs with waste.
Walls
Layout
Lumber list
Studs to buy
44
44 × 92⅝"
Plates
7 pcs
102 ft on 16-ft stock
Header stock
19.5 ft
Two-ply, opening + jack bearing
Sheathing
10 sheets
272 sq ft of wall + 8%
Quantities are half a bid. Send these to the free estimate builder to add labor, burden and markup, then hand the customer a proposal.
Every field takes arithmetic — type 24+18+12 and it adds. Nothing is sent anywhere; the math runs in your browser.
The stud formula
Field studs = wall length × 12 ÷ spacing, rounded up, + 1 for the closing end. A wall that is an exact multiple of the spacing does not get an extra: 16 ft at 16 inches on center is 12 spaces and 13 studs. Then the layout extras go on top — 2 per outside corner, 2 per T-intersection (a three-stud corner or ladder blocking), and a net 2 per opening — and waste is added to the total.
| Worked example: 20-ft wall, 16" o.c. | Studs |
|---|---|
| 20 × 12 ÷ 16 = 15 spaces, + 1 | 16 |
| 2 outside corners × 2 | + 4 |
| 2 openings × 2 | + 4 |
| Subtotal | 24 |
| With 10% waste | 27 |
The one-stud-per-foot rule of thumb
Many framers order one stud per linear foot of wall and let the extras sort themselves out. At 16 inches on center that builds in about 25% over the field count, which covers corners and openings on a cut-up floor plan but over-orders on long, plain walls. At 24 inches on center it over-orders badly. Counting the layout takes a minute and returns the difference to the bid.
Precut stud lengths
| Wall height | Precut stud | Why that length |
|---|---|---|
| 8 ft | 92⅝" | With a 1½" bottom plate and 3" double top plate, the wall is 97⅛" — room for 8-ft board plus the ceiling layer |
| 9 ft | 104⅝" | Same plate allowance for a 9-ft wall |
| 10 ft | 116⅝" | Same plate allowance for a 10-ft wall |
Headers and sheathing
Header stock is figured as a two-ply header spanning each opening plus 1½ inches of jack-stud bearing on each side. The header size itself depends on span, load, snow and building width, and is set by the plans or the IRC header span tables (R602.7) — this calculator counts length, not size. Sheathing is 4 × 8 sheets over the gross wall area plus 8%, hung over openings and routed out afterward.
Framing is the first trade on the wall. Carry the same walls into the drywall calculator and siding calculator, price labor per linear foot in the estimate builder, or see the assemblies in the framing estimating software.
Frequently asked questions
How many studs do I need for a 10-foot wall?
At 16 inches on center, 10 ft × 12 ÷ 16 = 7.5, which rounds up to 8 spaces, plus 1 for the end: 9 studs. Add 2 for each corner or intersecting wall and about 2 for each window or door, then 10% waste.
How do you calculate studs for a wall?
Studs = wall length in inches ÷ spacing, rounded up, + 1. Then add the extras the layout needs: 2 per outside corner, 2 per T-intersection, and a net 2 per opening for the king and jack studs. A 20-ft wall with 2 corners and 2 openings at 16 inches on center is 16 + 4 + 4 = 24 studs, or 27 with 10% waste.
How many extra studs per window or door?
Each opening gets a king and a jack on both sides — four studs — but it displaces the field studs that would have landed in the opening, and cripples above and below are often cut from offcuts. Net, most framers add about 2 per ordinary opening; wide or structural openings need more.
Should I frame 16 or 24 inches on center?
16 inches is the default for most walls and gives drywall and siding more backing. The IRC allows 24 inches on center for many 2 × 6 bearing walls and for non-bearing walls, within the limits in its stud size and spacing table (R602.3(5)); advanced framing uses it to cut lumber and thermal bridging. Confirm with the plans and the local code official.
How much plate material do I need?
Three linear feet of plate per foot of wall for a single bottom plate and a double top plate. A 60-ft run of wall takes 180 ft of plate, or 12 pieces of 16-ft stock before waste.
Quantities are half the bid.
BuiltSum prices them from trade assemblies, sends the proposal, and bills the job monthly — unlimited projects from $49/mo.
Start free