How Wall Studs are Calculated
Wall studs are the vertical framing members that form the structure of a wall. The calculation is based on the "on-center" spacing, which is the distance from the center of one stud to the center of the next.
The basic formula is to divide the total length of the wall (in inches) by the spacing (in inches), and then add one stud for the end. For example, a 10-foot (120-inch) wall with 16-inch spacing needs (120 / 16) + 1 = 7.5 + 1 = 8.5. Since you can't have half a stud, you round up to 9 studs.
Common Stud Spacing
| Spacing | Common Use | Pros & Cons |
|---|---|---|
| 16" On Center | Standard for load-bearing walls and exterior walls. | Strong, provides a solid backing for drywall. The industry standard. |
| 24" On Center | Often used for non-load-bearing interior walls. | Saves on lumber costs and provides larger cavities for insulation. May not be suitable for all load requirements. |
How to Use the Calculator
- Enter the total linear length of the wall you are building.
- Select the on-center spacing for your studs. 16 inches is the most common.
- Click "Calculate Studs" to see the total number of vertical studs needed.
- The calculator also reminds you to purchase lumber for the top and bottom plates (the horizontal members). A standard wall has one bottom plate and a double top plate.
Frequently Asked Questions
Does this calculator include extra studs for corners or window/door frames?
No. This calculator provides a basic estimate for a simple, straight wall. You must manually add extra studs for corners (typically 2-3 extra studs), intersections with other walls, and the framing around windows and doors (king, jack, and cripple studs).
What are "plates"?
Plates are the horizontal boards that form the top and bottom of the wall. The vertical studs are nailed between them. A typical wall has one bottom plate and two top plates (a "double top plate") for added strength and to help tie walls together.