How to calculate wall framing
The number of vertical studs in a wall depends on its length and the spacing between studs. The base formula is:
Studs = (wall length × 12 ÷ on-center spacing) + 1
The “+ 1” is the stud at the far end of the wall. On top of those field studs, you add framing for each opening (king and jack studs), extra studs at corners and where partition walls meet, and a little waste for bad cuts. This calculator adds two studs per opening and your chosen waste percentage on top of the field studs.
Studs, plates, and spacing
A framed wall is more than studs. It has a bottom plate the studs sit on and, on a load-bearing wall, a double top plate — so the plate lumber runs the length of the wall three times.
| Spacing | When it's used |
|---|---|
| 16″ on-center | Standard for load-bearing and exterior walls |
| 24″ on-center | Non-load-bearing walls and advanced framing — less lumber |
| 12″ on-center | Heavy loads or tall walls that need extra strength |
Good to know
- Precut studs save cutting. A standard 8-foot wall uses 92⅝″ precut studs, which leaves room for the bottom plate and double top plate under an 8-foot drywall sheet.
- Openings need headers. Doors and windows need a header sized to the span (often doubled 2×8s or larger) plus cripple studs above and below — extra lumber this estimate doesn't price.
- Buy a little extra. A 10% waste allowance covers crooked boards and miscuts; bump it up for a wall with lots of openings.