How many studs a wall needs
For a straight wall: studs = floor(wall length in inches ÷ spacing) + 1. A 20 ft wall at 16-inch on-center spacing needs floor(240 ÷ 16) + 1 = 16 studs, before extras for corners and openings. Add a top and bottom plate: a double top plate plus single bottom plate is about 3× the wall length in lumber. Once framed, the sheet count comes from the drywall calculator.
How to use this calculator
Enter the wall length in feet and the stud spacing on-center (16 inches is standard; 24 inches is used for some walls). The result shows the base stud count, a padded count for corners and waste (about 15%), and the linear feet of plate lumber.
16-inch vs. 24-inch spacing
16-inch on-center is the most common spacing — stronger and friendlier to drywall and fixtures. 24-inch on-center uses less lumber and suits some load-bearing and energy-efficient framing, but needs thicker sheathing or drywall. Always follow local code for the wall's role. Wall areas are measured with the square footage calculator.
Don't forget openings and corners
Doors and windows need king studs, jack studs, headers, cripples and sills — and corners need extra studs for backing. The padded count covers rough waste, but add specific framing members for each opening. For lumber volume pricing, see the board foot calculator.
Frequently asked questions
- How do I calculate the number of studs in a wall?
- Divide wall length in inches by the spacing, round down, then add 1. A 20 ft wall at 16-inch spacing needs about 16 studs before corners and openings.
- What is standard stud spacing?
- 16 inches on-center is the most common. 24-inch on-center is used in some framing to save lumber but needs thicker sheathing or drywall.
- How much extra lumber should I buy?
- Add about 10–15% for corners, blocking, waste, and the framing around doors and windows.
- How much plate lumber do I need?
- A double top plate plus a single bottom plate is about three times the wall length in linear feet.
- How do doors and windows change the stud count?
- They usually increase it. You lose the studs inside the opening but gain two king studs, two jack studs, a header and cripples above and below, so each opening is a net addition of several pieces.