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Stud Calculator

Enter your wall length and stud spacing to get the number of studs plus the plate lumber for framing.

Quick answer: To find the number of studs in a wall, divide the wall length (in inches) by the on-center spacing and add one for the end: studs = ⌊length × 12 ÷ spacing⌋ + 1, plus extra for corners and openings. A 20 ft wall at 16 in on center needs about 16 studs before corners and openings. Plate lumber runs the full wall length times the number of plates (usually a doubled top plate + single bottom = 3).
Total wall run.
3 = double top + single bottom.
Studs (incl. end + waste)
Studs by spacing
Plate lumber (linear ft)
Wall length

Adds 2 studs for corners/openings; real framing needs extra for windows, doors, corners, and blocking. Follow local code. Estimate only.

No sign-up No ads Runs in your browser — your numbers never leave your device

Framing a wall

Studs sit at a set spacing — 16 or 24 inches on center — plus one to close the end. Plates run the full wall length top and bottom (the top is usually doubled), so plate lumber is the length times the number of plates.

Studs = ⌊length×12 ÷ spacing⌋ + 1 (+ corners) · Plate lumber = length × plates

Framing a wall: studs, plates, and the extras plans forget

A stud wall is simpler than it looks once you separate the two lumber jobs. Studs stand vertically at a fixed spacing; plates run horizontally along the top and bottom. The base stud count is ⌊wall length in inches ÷ on-center spacing⌋ + 1 (the “+1” closes the far end), and plate lumber is simply the wall length times the number of plates (usually a doubled top plate plus a single bottom = three lengths).

A worked example

A 20 ft wall at 16 inches on center: 20 × 12 = 240 inches, ÷ 16 = 15, + 1 = 16 studs before extras. Plates: 20 ft × 3 = 60 linear feet of plate stock. Switch to 24-inch spacing (common in some non-load-bearing or advanced-framing walls) and the same wall drops to 11 studs — real lumber savings, but only where the plans and local code allow it.

The extras a raw count misses

Treat the calculator’s number as the base framing count and add for corners and openings before you buy. Follow the approved plans and local building code — spacing and structural requirements are not optional. Pouring a footing for that wall? The concrete calculator sizes it.

Quick FAQ

16 or 24 inch spacing?

16" on center is the residential standard for load-bearing walls; 24" saves lumber and is common for some non-load-bearing or advanced-framing walls. Follow the plans and code.

What about windows and doors?

Openings need king and jack studs, headers, cripples, and blocking — add material beyond this base count.

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More questions

Is the Stud Calculator free to use?

Yes. The Stud Calculator is completely free, runs in your browser, and never asks for a signup, email, or download. Enter your numbers and the result updates instantly.

How accurate is this calculator?

It uses standard formulas and recalculates the moment you change a value, so the math is exact for the inputs you enter. Treat the result as a reliable planning estimate; for decisions with legal or tax consequences, confirm the figures with a qualified professional.

Does it work on my phone?

Yes. The calculator is mobile-friendly and works on any phone, tablet, or computer — there is no app to install and nothing to save.

Can I add this calculator to my own website?

Yes. Scroll to “Add this free calculator to your site” above and copy the embed snippet to place the live calculator on your blog or website for free.

Last reviewed: September 2026. Free to use, no signup — Stud Calculator by ToolWise Digital.

Add this free calculator to your site

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