Framing Calculator
Calculate studs, plates, and headers needed for wall framing including doors and windows. See also our Lumber Calculator, Drywall Calculator, and Floor Joist Calculator.
How to Use the Framing Calculator
Enter the wall length and height in feet. Select stud spacing — 16" OC is standard for load-bearing walls, while 24" OC (advanced framing) is acceptable for non-load-bearing interior walls and some exterior walls with proper engineering. Enter the number of doors and windows in the wall. The calculator accounts for king studs, jack studs, cripple studs, double top plates, bottom plate, and headers for each opening. Results include total stud count and board feet for material ordering.
Formula
Regular Studs = (Wall Length x 12 / Spacing) + 1
King Studs = (Doors + Windows) x 2
Jack Studs = (Doors + Windows) x 2
Cripple Studs = Windows x 4 + Doors x 2
Plates = 3 x Wall Length (2 top + 1 bottom)
Headers = 1 per opening (doubled 2x10 or 2x12)
Example Calculation
Wall: 20 ft long, 8 ft high, 16" OC, 1 door, 2 windows
Regular studs = (240 / 16) + 1 = 16 studs
King studs = 3 openings x 2 = 6
Jack studs = 3 openings x 2 = 6
Cripple studs = 2 windows x 4 + 1 door x 2 = 10
Total studs = 16 + 6 + 6 + 10 = 38 studs
Plates = 3 x 20 ft = 60 linear feet of 2x4
Headers = 3 (doubled 2x10)
Reference Table: Framing Lumber
| Component | Typical Size | Length | Notes |
|---|---|---|---|
| Wall studs | 2x4 or 2x6 | 92-5/8" or 8 ft | Pre-cut or standard |
| Top/bottom plates | 2x4 or 2x6 | Wall length | Double top plate |
| Headers (3-4 ft span) | 2x6 doubled | Opening + 3" | Non-bearing walls |
| Headers (4-6 ft span) | 2x8 doubled | Opening + 3" | Load-bearing walls |
| Headers (6-8 ft span) | 2x10 doubled | Opening + 3" | Load-bearing walls |
| Headers (8-10 ft span) | 2x12 doubled | Opening + 3" | Load-bearing walls |
| King studs | 2x4 or 2x6 | Full height | 1 each side of opening |
| Jack studs | 2x4 or 2x6 | Header height | Support header |
Frequently Asked Questions
What is the difference between 16" and 24" OC framing?
16" OC (on center) places studs every 16 inches and is standard for load-bearing walls and most residential construction. 24" OC uses fewer studs, saves material (about 30% less lumber), and allows more insulation space. It's acceptable for non-load-bearing walls and some exterior walls with proper engineering and thicker sheathing.
What size header do I need?
Header size depends on the opening width and whether the wall is load-bearing. For load-bearing walls: openings up to 4 ft use doubled 2x6, 4-6 ft use doubled 2x8, 6-8 ft use doubled 2x10, and 8-10 ft use doubled 2x12. Non-load-bearing walls can use flat 2x4 headers for any opening width. Always verify with local codes.
Why do walls have double top plates?
Double top plates serve multiple purposes: they tie intersecting walls together (overlapping at corners and T-intersections), distribute loads from above across multiple studs, allow for slight misalignment in stud placement, and provide nailing surface for ceiling joists or trusses that may not align with studs below.
What are king studs and jack studs?
King studs run full height from bottom plate to top plate on each side of an opening. Jack studs (also called trimmer studs) are shorter studs that support the header — they run from the bottom plate to the underside of the header. Together, they transfer the header load down to the foundation. Each opening needs one king and one jack stud on each side.
Should I use 2x4 or 2x6 for exterior walls?
2x6 exterior walls are increasingly common because they allow R-19 or R-21 insulation versus R-13 or R-15 in 2x4 walls. Many energy codes now require 2x6 exterior walls or equivalent insulation values. 2x6 walls also provide more structural strength for multi-story buildings and better accommodate modern plumbing and electrical.
How many studs do I need per linear foot of wall?
At 16" OC spacing, you need approximately 1 stud per linear foot of wall (0.75 studs per foot plus extras for corners and openings). A common rule of thumb is to multiply wall length in feet by 0.75 and add 1 for the end, then add extras for openings. For 24" OC, use 0.5 studs per linear foot plus extras.