Stud calculator

Studs, plates and total linear feet of lumber for a framed wall.

Total run of the wall.
Floor to top plate.
16 or 24 on center.
Doors and windows. Each adds 4 studs.
3 = single bottom + double top.
Runs entirely in your browser — nothing you enter is uploaded or stored. Estimates only: always confirm quantities with your supplier before ordering.

Detailed breakdown

ItemQuantity
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How to use this calculator

1

Measure

Enter the wall length and height in feet, your stud spacing, and how many door or window openings it has.

2

Calculate

Once you hit calculate, results update as you type. Change any number to compare options instantly.

3

Order

Print the estimate and take it to your supplier. Quantities are rounded up so you don't come up short.

You need one more stud than the arithmetic gives you

Last reviewed: .

Stud counts fail in the same place rebar counts do: the last one. This is the fencepost problem — a 40 foot wall at 16 inches on center has 30 gaps and 31 studs, because you need a stud at both ends. Divide 480 inches by 16, stop at 30, and you'll be a stud short on every wall you frame.

Openings each add roughly four studs — a king stud and a jack stud on both sides. So one door in that 40 foot wall brings the count to 35 studs. Corners and wall intersections need extras too: add two per corner, more if you are framing a three-stud corner rather than a two-stud with drywall clips.

Plates are usually the forgotten line on the lumber order. A standard wall has a single bottom plate and a double top plate, which is three times the wall length — 120 linear feet on a 40 foot wall. With 35 studs at 8 feet that's 280 linear feet of stud, so 400 linear feet of lumber in total.

This count does not include headers, and it cannot: a header is sized by its span and the load above it, and a bearing wall carrying a roof needs a very different member than a partition wall carrying nothing. Span tables from the American Wood Council or your local code will tell you what the opening needs. Twenty-four inch spacing is allowed for many non-bearing walls and for 2x6 bearing walls, and it saves lumber — but check what your local code allows before you frame to it.

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Frequently asked questions

How many studs for a 40 foot wall?

Thirty-one at 16 inches on center before openings, because you need a stud at each end. One door or window adds about four more.

How many studs per opening?

About four: a king stud and a jack stud on each side. The header itself is separate and is sized by span and load.

How do I calculate plate lumber?

Three times the wall length for a standard wall — one bottom plate and a double top plate. A 40 foot wall needs 120 linear feet.

Is 24 inch stud spacing allowed?

For many non-bearing walls and for 2x6 bearing walls, yes, and it saves lumber. Check your local code, since what is permitted depends on load and member size.

Does this include headers?

No. Headers are sized by span and the load above, using span tables or an engineer. A calculator cannot size one safely.

Sources

Formulas and material assumptions on this page follow published industry guidance:

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