Wall Stud Calculator

Understanding your result

The headline is the number of studs to buy, at the precut length your wall height takes, with the waste allowance in. The line under it gives the count before waste. The tiles split the count into the field studs, the studs around openings, and the plate length.

The table lists every kind of stud on its own line, which is how the count is checked on site. Field studs are the regular rhythm along the wall; the studs that would land inside a door or window are removed; each opening adds a king and a jack on each side and cripples above (and below a window); corners add two studs to give both walls a nailing surface; and each place another wall tees in, or the wall meets an existing one, adds a nailer so the drywall in the corner has something to fasten to.

The plates come out at three times the wall length. The plates and blocking calculator turns that into stock lengths with offset joints and adds the blocking; the rough opening calculator gives the opening sizes this page asks for. To get the drywall, screws and compound for the same wall in one list, use the partition wall calculator.

How we calculate this

The stud length comes from the wall height: precut studs are made so that a stud, one bottom plate and two top plates (4-1/2 in together) give the standard wall heights. A 92-5/8 in precut makes a 97-1/8 in wall, which is a 96 in sheet of drywall plus a gap at the floor. The standard heights, stud spacings and precut lengths are on the standard sizes table.

The opening count is the common way of framing an opening in a partition; it is generous in one respect, because many framers skip jack studs in non-bearing walls and hang the header between the kings. Keeping them gives the door frame a solid side and costs two studs.

The assumptions behind the numbers

Assumptions last reviewed October 8, 2026.

This is a count for non-load-bearing walls only. It does not size headers, check stud heights against the code limits for bearing walls, or handle walls that support joists, a ridge, a beam or a floor above; those walls need the span tables in IRC R602 and, where in doubt, an engineer. It also does not count the extra studs plumbers and electricians sometimes ask for. How a partition goes together, from layout lines on the floor to the last cripple, is in the guide to framing a partition wall; steel studs are counted differently, as the metal vs wood studs guide explains.

Two worked examples

Where to find your inputs

Length and height. Snap the wall line on the floor and measure it; measure the height from the floor to the joists or ceiling where the top plate will go.

Openings. The rough opening width of each door and window: 2 in more than a pre-hung door’s slab, 1/2 in more than a window unit. The rough opening calculator gives the exact figure.

Corners and tees. Count each 90° turn of the new wall and each place it meets an existing wall or another new wall coming in at a right angle.

Spacing. Sixteen inches unless you have a reason; 24 in for long, plain partitions and garages.

Common mistakes

• Treating a bearing wall as a partition. If joists rest on the wall, it is bearing. Stop and use the span tables.
• Forgetting the nailers. A drywall corner with nothing behind it cracks. One stud for each tee.
• Laying out from the wrong end. Lay out from the end where the first sheet of drywall starts, so sheet edges land on studs.
• Full-length studs for an 8 ft wall. An 8 ft stud plus three plates is too tall. Precuts.
• No cripples over the header. The drywall above the door needs studs at the spacing.
• Buying exactly the count. Some studs are crooked. Ten percent spare, and return the unused ones.

Questions people ask

How many studs do I need for a 20 ft wall?

At 16 in on centre, 240 in ÷ 16 + 1 = 16 field studs. A 34 in door opening removes two of them and adds two king studs, two jack studs and two cripples above the header, and two nailers where the ends meet existing walls bring the wall to 22 studs, 25 with 10% for crooked ones.

Is one stud per foot a good rule?

It is a rough check, not a count. A wall at 16 in on centre has three studs for every four feet plus the end stud, and openings, corners and nailers add more. On a 20 ft wall with a door, "one per foot" says 20 and the real count is about 22; at 24 in on centre it says 20 and the real count is about 17.

What length studs for an 8 ft wall?

92-5/8 in precut studs. With one bottom plate and two top plates, each 1-1/2 in thick, they make a wall 97-1/8 in tall, which takes a 96 in sheet of drywall with a little room at the floor. For 9 ft walls the precut is 104-5/8 in and for 10 ft walls 116-5/8 in.

16 or 24 inch stud spacing for an interior wall?

Either, for a non-load-bearing partition. Sixteen inches is stiffer and the usual choice, and 1/2 in drywall is screwed at 16 in. Twenty-four inches saves about a quarter of the studs; walls then need fasteners at 12 in and feel softer, and long runs of cabinets want the closer spacing.

What are king, jack and cripple studs?

King studs run full height on each side of an opening. Jack (trimmer) studs are nailed to the kings and carry the header. Cripples are short studs above the header, and below a window sill, that keep the stud rhythm so the drywall has something to fasten to.

Do I need a header in a non-load-bearing wall?

A small one. A flat 2 × 4 or a doubled 2 × 4 on edge over the jacks is usual; it carries the cripples and gives the drywall and the door casing something solid. A bearing wall's header is sized from the span tables in IRC R602.7, often a doubled 2 × 8 or larger.