Free Framing Calculator — Studs, Plates & Headers

How to Use the Framing Calculator

How to Calculate Wall Framing Materials

The core formula for estimating field studs is straightforward: Field Studs = ceil(Wall Length ÷ On-Center Spacing) + 1. That gives you the evenly spaced studs running the length of the wall. But a real wall also needs king studs and jack (trimmer) studs flanking every door and window opening, plus cripple studs above headers and below window sills to maintain the on-center layout. For corners, you need a 3-stud corner assembly to provide a nailing surface for drywall on both sides. Add all of these together and you have a complete stud count. For example, a 20-foot wall at 16" on-center with one 36" door and two 30" windows requires 16 field studs + 6 king studs + 6 jack studs + roughly 10 cripple studs = approximately 38 studs total. This framing calculator handles all of that math automatically — enter your wall dimensions, add openings, and get a precise material list in seconds.

Understanding Stud Types

Every stick of lumber in a framed wall serves a specific structural purpose. Understanding the five stud types helps you read framing plans, estimate materials accurately, and build walls that pass inspection:

• Field studs are the regular studs spaced at 16" or 24" on-center along the entire wall length. They transfer roof and floor loads to the bottom plate and foundation. Field studs run full height from the bottom plate to the top plate and form the backbone of the wall assembly.
• King studs are full-height studs that flank each side of a door or window opening. They run from the bottom plate to the top plate just like field studs, but their purpose is to anchor the header assembly and transfer the concentrated load around the opening down to the foundation.
• Jack studs (trimmers) are cut shorter than field studs and sit tight against the king studs. They support the header directly from below and define the exact rough opening height. Each opening gets one jack stud per side (two per side for spans over 6 feet or per local code requirements).
• Cripple studs are short studs that fill the space above a header up to the top plate, or below a window sill down to the bottom plate. They maintain the on-center stud layout through the opening so sheathing and drywall have consistent nailing at 16" or 24" intervals. Cripples are not full height and carry no direct vertical load, but they are required for sheathing attachment and lateral bracing.
• Corner studs use a 3-stud assembly (or 2-stud with drywall clips) at each wall intersection. The classic method uses three studs arranged in an "L" or "U" shape so that both the inside and outside walls have a solid nailing surface for drywall. Advanced framing (OVE) techniques use two studs with inexpensive drywall clips to reduce lumber and improve insulation coverage in the corner cavity.

Header Sizing

Headers span across door and window openings to carry the load that the removed studs would have supported. In load-bearing walls, header sizing depends on the span width and the loads above. Standard residential header sizes for single-story load-bearing walls are:

• 2×6 header for openings up to 3 feet
• 2×8 header for openings up to 4 feet
• 2×10 header for openings up to 5 feet
• 2×12 header for openings up to 6 feet

A built-up header is constructed from two pieces of dimensional lumber with a 1/2" plywood spacer sandwiched between them. This brings the total header thickness to 3-1/2", matching the width of a 2×4 wall. For 2×6 walls, use a 3/4" spacer to reach 5-1/2". In non-load-bearing (partition) walls, headers are not structurally required — a single flat 2×4 or even cripple studs above the opening are sufficient, though many framers install headers anyway for consistency and to simplify drywall backing.

Plates and Layout

Every stud wall requires three horizontal plates: a bottom plate (sole plate), a top plate, and a cap plate (tie plate or double top plate). The bottom plate and top plate are cut to the full wall length. The cap plate overlaps the top plate joints and extends across wall intersections by at least 48" to tie adjacent walls together — this is a code requirement (IRC R602.3.2) that provides lateral continuity across the building frame.

For the bottom plate, subtract the width of any door openings because the plate is cut away at doorways after the wall is raised. Window openings do not affect the bottom plate — it runs continuously under windows to support the sill and cripple studs. Plate material is the same stock as the studs: 2×4 for standard walls, 2×6 for exterior walls in cold climates or where required by energy code. Calculate total plate material as 3 × wall length, minus the door opening widths from the bottom plate only.

Pro Tips

• Pre-cut studs (92-5/8") save significant time for standard 8-foot walls with a double top plate and a single bottom plate. Three plates at 1-1/2" each = 4-1/2", so 96" − 4-1/2" = 91-1/2" — but the standard pre-cut stud is 92-5/8" to account for the slight compression under load and drywall clearance. These are sold as "stud grade" or "pre-cut" at every lumber yard and eliminate the need to measure and cut every stud individually.
• Crown all studs before nailing — sight down the edge of each stud and mark the crowned (bowed) side. Install all crowns facing the same direction (typically toward the exterior or toward one consistent side) so the wall plane is as flat as possible. Badly crowned studs should be cut up for cripples or blocking, not used as full-height studs.
• Layout from one end consistently — hook your tape at the same end of the wall for both the top plate and bottom plate. Mark every 16" (or 24") increment with a line, then draw an "X" on the side of the line where the stud goes. This ensures studs align vertically for sheathing panels and drywall sheets to land on center.
• Check for crown in plates and lay crown up on the bottom plate. When the bottom plate sits on the subfloor, any bow facing up will be pressed flat by the weight of the wall. If the bow faces down, it creates a gap under the center of the plate that can cause squeaks and fastener problems.
• Order 5–10% extra studs for bowed lumber, splits, and cutting mistakes. Lumber yards typically allow returns on full-length studs, but running short mid-project means a trip to the yard and lost time. For large framing jobs, a 10% overage is standard practice.