This stud calculator counts the studs in a framed wall at 16″ or 24″ on center — plus the plate lumber (bottom plate + double top plate) that the wall needs — so the lumber run buys the wall in one trip.
Plates = 3 × wall length (one bottom plate + doubled top plate). Order ~10% extra studs beyond the total for culls — lumber yards ship some bananas and call them studs.
The Framer’s Formula
Studs divide the wall into equal spaces: studs = (wall length ÷ spacing) + 1 — the +1 is the end stud that pure division always forgets. Real walls then need more: corners take 2–3 studs for drywall backing, intersecting walls need ladder or California corners, and every door/window adds king, jack and cripple studs. The calculator’s extras field (default 4) is where those live. Skin the finished frame with our Drywall Calculator and price the pile with the Board Foot Calculator. Part of our Construction Calculators collection.
Worked Example (Verified)
A 16 ft wall at 16″ on center:
- Spaces: 192″ ÷ 16″ = 12 → layout studs = 12 + 1 = 13
- With 4 extras for corners/openings: 17 to buy (plus the 10% cull allowance your temper will thank)
- Plates: 3 × 16 = 48 linear feet — three 16-ft boards or six 8s
- The same wall at 24″ OC: 8 spaces + 1 = 9 layout studs — legal for many non-load-bearing and some load-bearing walls, but drywall and tile prefer 16″.
Framing Notes From the Code Book’s Spirit
- 16″ OC is standard because drywall, plywood and insulation are all manufactured around it; 24″ OC saves lumber but flexes more under tile and needs the wall’s loads checked.
- Load-bearing walls want studs stacked under joists/rafters above; advanced framing (24″ OC, single top plate, ladder corners) is an engineered system, not a random omission.
- Buy studs by eye: sight down each one for crook and bow. The calculator counts studs; only you can reject the propeller-shaped ones.
- Openings: a door roughly adds 4–6 studs (2 kings, 2 jacks, header cripples); windows similar plus a sill. Bump the extras field accordingly.
Related Tools
- Drywall Calculator — covering the frame
- Board Foot Calculator — lumber volume & cost
- Construction Calculators — the full collection
Frequently Asked Questions
How many studs do I need for a 16-foot wall?
13 layout studs at 16″ on center (12 spaces + 1 end stud), plus extras for corners and openings — 17 is a realistic buy count for a simple wall with a door, before the 10% cull allowance.
What does “16 inches on center” mean?
The distance from the center of one stud to the center of the next is 16 inches — so each bay fits standard insulation and the stud edges land where 4×8 sheet goods expect them (every 48″ a stud center aligns with a sheet edge).
How many studs per linear foot should I estimate?
The framer’s rule of thumb is about 1 stud per linear foot at 16″ OC once corners, openings and waste are folded in — deliberately more generous than the bare layout count (0.75/ft).
Do I need a double top plate?
On load-bearing walls, yes in conventional framing — the second plate ties wall segments together and spreads loads (and the calculator includes it: plates = 3 × length). Single top plates exist in engineered advanced framing with aligned loads.
What size studs should I buy?
2×4 for standard interior and most exterior walls (2×6 where plumbing, insulation depth or height demands). Lengths: pre-cut 92⅝″ studs are sized for 8-ft walls with plates — the yard sells them precisely for this.
Is this stud calculator free?
Yes — free, instant, no sign-up.