Stud Calculator

Framing lumber is sold in fixed stock lengths, so the calculator reports plates in linear feet and leaves the rounding to you.

How to use this calculator

1. Measure the wall's length along the floor, end to end, in feet. For an L-shaped wall, run the calculator for each straight section and add the totals.
2. Pick the stud spacing from the menu to match your plans. The starting value is a common choice, not a rule.
3. Open More options and enter the extra studs for corners and openings, counted from the plan.
4. Set identical walls to the number of matching walls. If the walls differ, run each wall separately and add the results.
5. If the length does not divide evenly by the spacing, the calculator still puts a stud at the far end, so the last bay is simply shorter.
6. If your yard prices lumber by the board foot, use the board feet calculator to convert piece sizes into that price.

Worked examples

Studs needed for common wall lengths at each usual spacing

Each cell: Studs. Inputs not in the table use the calculator's starting values.

How the stud count is built

The calculator places a stud at the start of the wall and at every spacing mark along it. The extra studs are added to each wall first, and the headline total then multiplies the per-wall figure by the identical walls.

The plate figure covers the bottom plate on the floor and the doubled top plate above the studs. It is a length in linear feet, not a count of pieces, and it scales with the number of walls too.

When the length is not a whole number of spacings, the last bay is short, and the far-end stud is the easiest to miss in a hand count; the calculator includes it.

Spacing on center and layout

Spacing on center, or OC, runs from the middle of a stud to the middle of the next. The common spacing is 16 inches, with 16 to 24 inches in common use.

Mark the stud positions on the bottom plate, carry the marks across to the top plate, and check the far-end bay before you nail anything.

After the frame is up, the sheets for its face come from the drywall calculator, which works from wall area, not from the studs.

Extra studs for corners and openings

The calculator cannot see your corners and openings, so the extra studs are a plain figure you add to each wall. A corner needs extra framing so the wall covering has solid wood to fasten to at the turn.

A door or window opening needs king studs, full height on each side, and jack studs beside them to carry the header. Cripple studs fill the space above a door header or below a window sill.

Blocking is a short piece set between studs to support a fixture or a board edge. Count it as lumber on its own, not as extra studs.

Stud size, spacing and headers for load-bearing walls are set by the building code and your local building department. This calculator gives no stud sizes or spans, so check those before you frame a load-bearing wall.

Mistakes to avoid

• Leaving out the king, jack and cripple studs around openings. Enter them under extra studs.
• Stopping at the far end of an uneven wall. A stud belongs there whether or not the length divides evenly.
• Using the stud count for ceiling joists or rafters. Those follow their own spacing and span rules.

Common questions