Standard Wall Thickness (Interior & Exterior)
Part of Interior & Finishes
Quick answer
A standard interior wall is about 4.5 inches thick: a 3.5-inch 2×4 stud with 1/2-inch drywall on both sides. Interior 2×6 walls are about 6.5 inches, and exterior walls typically run 6.5 to 8+ inches once sheathing and siding are added.
Wall thickness is the framing depth plus the finish on each face. Knowing it matters for door jamb width, trim, and fitting things like pocket doors or recessed fixtures.
Typical finished wall thickness
| Wall type | Framing | Finished thickness |
|---|---|---|
| Interior (standard) | 2×4 (3.5 in) | ~4.5 in |
| Interior (plumbing/2×6) | 2×6 (5.5 in) | ~6.5 in |
| Exterior (2×4 + sheathing) | 2×4 | ~6.5–7.5 in |
| Exterior (2×6 + sheathing) | 2×6 | ~8+ in |
These assume 1/2-inch drywall. Add 1/4 inch if you have 5/8-inch board, and more for double-layer or soundproofed walls. Exterior totals depend on the sheathing, insulation board, and siding used.
FAQs
How thick is a standard interior wall?
About 4.5 inches: a 3.5-inch 2×4 stud plus 1/2-inch drywall on each side. Walls hiding plumbing are often 2×6, making them about 6.5 inches.