Wall Stud Calculator — Framing Lumber & Board Count

    Calculate the exact number of studs, plates, headers, jack studs, and cripple studs needed to frame a wall. Supports standard stud spacings, door and window openings, and waste factors. Free to use — no signup required.

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    How to Use

    1. Enter the total wall length in feet (decimals are fine for partial feet).
    2. Select wall height — 8 feet is standard for most residential construction.
    3. Choose stud spacing — 16" on center is code for load-bearing walls.
    4. Enter the number of door and window openings in the wall.
    5. Select stud size — 2x4 for interior walls, 2x6 for exterior or insulated walls.
    6. Set a waste factor — 10% is recommended for typical framing.
    7. Optionally enter a price per stud for a cost estimate.
    8. Hit Calculate and get your complete framing material list.

    View lumber dimensions chart for nominal vs actual lumber sizes. See stud spacing reference for code requirements by wall type.

    Quick Reference — Studs per Wall

    Wall studs needed at 8-foot height, no doors or windows, no waste factor.

    Wall Length16" OC24" OC
    8 ft75
    10 ft96
    12 ft107
    16 ft139
    20 ft1611

    Example Calculation

    Framing a 20-foot wall at 8 feet tall with 16" OC spacing, one door, and one window using 2x4 studs with 10% waste? You need approximately 16 wall studs, 4 jack studs, 5 plate boards (double top plate + sole plate), 4 header boards, 2 cripple studs, and 1 sill plate — about 35 boards total.

    Common Framing Lumber Costs

    LumberTypical Price
    2x4x8 stud (SPF)$3.00 – $5.00
    2x4x10 stud$4.50 – $7.00
    2x6x8 stud (SPF)$5.00 – $8.00
    2x6x10 stud$7.00 – $10.00
    2x8x8 (headers)$7.00 – $11.00
    2x10x8 (headers)$9.00 – $14.00
    2x12x8 (headers)$12.00 – $18.00

    Frequently Asked Questions

    How many studs do I need for a 20-foot wall?

    At 16" on center spacing, a 20-foot wall needs 16 studs (240 inches / 16 + 1). Add jack studs and cripple studs for any door or window openings, plus 10% waste for cuts and defects.

    What is the difference between 16" OC and 24" OC stud spacing?

    16" on center is the standard for load-bearing walls and most residential construction per IRC code. 24" OC is allowed for non-load-bearing interior partition walls and can save 30-40% on lumber, but check your local building code first.

    How do I frame a header for a door or window?

    A standard header uses two 2x boards (2x6, 2x8, or 2x10 depending on span) with 1/2" plywood sandwiched between them. Headers sit on jack studs (trimmer studs) that carry the load down to the sole plate. A 3-foot opening typically uses a 2x6 header; wider openings need larger headers.

    What is the difference between a king stud and a jack stud?

    A king stud runs full height from the sole plate to the top plate and sits next to a door or window opening. A jack stud (trimmer stud) is shorter and sits inside the king stud, supporting the header directly. Every opening needs both king studs and jack studs on each side.

    Do I need a double top plate?

    Yes, in most cases. A double top plate is required by code on load-bearing walls to tie intersecting walls together and distribute loads. The joints in the two plates must be offset by at least 48 inches. Single top plates are only allowed in specific engineered wall systems.

    How much lumber waste should I plan for?

    10% waste is standard for most framing projects and covers mis-cuts, defective boards, and off-cuts that are too short to reuse. For complex walls with many openings, consider 15%. Experienced framers on simple walls can get by with 5%.