Stud Calculator

1. Enter the wall length in feet.
2. Pick the wall height (8, 9 or 10 ft).
3. Pick the stud spacing (16 or 24 in OC).
4. Enter the number of corners, doors and windows.
5. Optionally enter the price per stud for a cost estimate.
6. Read the stud count, plate footage and cost.

Here is what each result line means:

For the cost of those studs by board foot, see the rebar weight calculator and the concrete formwork calculator.

A stud calculator converts a wall length, spacing and opening count into the number of framing studs you need to buy. It also tells you how many linear feet of plate lumber the wall requires for the bottom and double top plates.

Carpenters, DIY builders and estimators use it to build a lumber list before going to the yard.

L is the wall length in feet, s is the spacing in feet (16 in = 1.333 ft, 24 in = 2 ft), C is the number of corner posts and O is the number of openings (doors plus windows). Each opening adds 2 king studs and 2 jack studs.

1. Divide the wall length by the spacing in feet and round up.
2. Add 1 for the end stud.
3. Add 1 per corner post.
4. Add 4 per door or window opening (2 king + 2 jack).
5. Multiply wall length by 3 for the plate stock (1 bottom + 2 top).

You are framing a 20-ft exterior wall at 16 inches on center, with 2 corner posts and 2 door openings.

Calculation: field studs = ceil(20 / 1.333) + 1 = 15 + 1 = 16. Corner extras = 2. Opening extras = 2 doors x 4 = 8. Total = 16 + 2 + 8 = 26 studs. Plates = 20 x 3 = 60 linear feet.

At $4.50 per stud, the stud cost alone is 26 x $4.50 = $117.

Spacing

Switching from 16 to 24 inches OC cuts the field stud count by about one-third, saving material on non-bearing walls.

Corners

Each corner post typically uses one extra stud beyond the field layout. Some codes require two- or three-stud corners for drywall nailing.

Openings

Each door or window adds at least 4 extra studs (2 king, 2 jack). Wide openings over 5 feet may need additional jack studs.

Intersecting Walls

A T-intersection where another wall meets this one adds 1 to 3 extra studs for backing.

Headers

The calculator counts king and jack studs but not the header lumber itself. Add that to your order separately.

The table below compares stud counts and costs for a 20-foot wall with 2 corners and 2 doors at different spacings.

The 24-inch layout saves 5 studs and about $22.50 on a single 20-foot wall.

New Construction

Build a lumber list for every wall in the floor plan.

Garage or Shop

Estimate studs for a detached structure with simple walls and few openings.

Basement Finishing

Count studs for partition walls at 16 or 24 inches on center.

Bid and Estimate

Price the framing package for a client proposal.

1. Forgetting Opening Extras

King and jack studs are easy to miss. Each opening adds 4 studs beyond the field layout.

2. Using the Wrong Spacing for Bearing Walls

Load-bearing walls typically require 16-inch spacing. Using 24-inch on a bearing wall can fail inspection.

3. No Waste Allowance

Add 10 percent for bowed, twisted or damaged studs. Pre-cut studs are better but still have culls.

4. Ignoring Intersecting Walls

Every T-intersection needs backing studs that the basic formula does not count.

5. Mixing Stud Lengths

A 92-5/8 stud fits an 8-foot wall, not a 9-foot wall. Ordering the wrong length means cutting or reordering.

The calculator uses the standard formula for platform framing with one extra stud per corner and 4 per opening. Complex layouts with many intersections, balloon framing or advanced framing need a detailed take-off.

At 16 inches on center with no openings or corners: ceil(10/1.333) + 1 = 8 + 1 = 9 studs. Add extras for corners and openings.

16-inch spacing puts studs closer together for more strength, required on most bearing walls. 24-inch saves material and is allowed on non-bearing walls or bearing walls supporting only a roof.

A full-height stud that runs from the bottom plate to the top plate, positioned on each side of a door or window opening to carry the header.

A shorter stud (trimmer) that runs from the bottom plate to the underside of the header, directly supporting the header. Each opening has at least one jack stud on each side.

92-5/8 inches for an 8-foot wall and 104-5/8 inches for a 9-foot wall. These lengths, combined with three 1.5-inch plates, produce the standard wall height.

The double top plate ties walls together at corners and intersections and distributes the load from above. The IRC requires it in standard platform framing.

Yes. Add about 10 percent for bowed, twisted or split studs that cannot be used.

No. The calculator counts king and jack studs but not the header beams or cripple studs. Order header lumber separately based on the opening width.

Only if it supports a roof and ceiling and no floor above, per IRC Table R602.3(5). Most bearing walls under a second floor need 16-inch spacing.

No. The calculation runs entirely in your browser and nothing you enter is stored or sent anywhere.

• International Code Council, IRC Table R602.3(5) (stud size, height and spacing for bearing and non-bearing walls).
• Journal of Light Construction, pre-cut stud lengths (standard stud lengths for 8- and 9-foot walls).
• InchCalculator, stud calculator method (framing count formula and opening extras).