Wall framing and stud calculator

How studs and plates are calculated

Start with the studs that fall on layout along the wall, then add the extra members for every corner, intersection and opening. Round each count up, because you can't buy part of a stud.

With several walls, each wall gets its own count, including its own end stud, and the counts are added. Walls of different heights take different precut studs, so the waste is applied and rounded up separately for each height. Door cripples sit above the header only. Window cripples sit above the header and again below the rough sill, so a window counts them twice. The plates, headers and sills are lineal feet:

Worked example: 40 ft wall at 16 in on center

The calculator opens on a 40 ft wall, 8 ft tall, studs at 16 in on center, with 2 outside corners, 1 door at 36 in and 2 windows at 36 in, plus 10% waste.

1. Field studs: 480 in ÷ 16 = 30 spaces, plus one = 31.
2. Corners: 2 × 2 = 4. No T-intersections, so 0.
3. Door: 36 ÷ 16 = 2.25, rounded up to 3 cripples, so 2 + 2 + 3 = 7.
4. Windows: 2 × (2 + 2 + 2 × 3) = 20.
5. Subtotal 62; with waste 62 × 1.10 = 68.2, rounded up to 69 studs, 92-5/8 in precut.
6. Plates: 3 × 40 = 120 lin ft, or 7.50 boards rounded up to 8 at 16 ft.
7. Headers: 2 × (39 + 2 × 39) ÷ 12 = 19.5 lin ft. Sills: 2 × 39 ÷ 12 = 6.5 lin ft.

Stud spacing and code notes

For a quick count by wall length at 16 and 24 in on center, with plates and corner studs, see the studs per foot chart.

Header depth depends on the span, the load above and the building width, so this calculator gives lineal feet, not a size. Look up the header in IRC Tables R602.7(1)–(3) or get it from your plans. Openings wider than 6 ft usually need an engineered header and often a second jack stud at each end; add those studs by hand.

Precut studs are sized so the framed wall comes out a little over the nominal height: 92-5/8 in plus 3 plates at 1½ in gives 8' 1-1/8".

Ordering tips

• Enter each wall on its own with “+ Add another wall”, so every wall keeps its own height, corners and openings. A 10 ft garage wall next to 8 ft house walls gets its own precut stud count. Past 200 ft, split a wall line so you can plan plate splices.
• Count a T-intersection wherever an interior wall meets this one. Ladder blocking between two layout studs can replace the 2 extra studs.
• Stagger top plate splices; IRC R602.3.2 requires end joints in a double top plate to be offset at least 24 in.
• The count leaves out backing for cabinets, grab bars and drywall, fire blocking and extra studs at outlets. Add them, or raise the waste.
• Sight each stud for crown at the yard and set the crowns the same way in the wall.