Framing Calculator

Base studs: ⌈20 ÷ (16/12)⌉ + 1 = 15 + 1 = 16. Add corner and opening extras on top.

Three runs of single plate equal 3 x wall length in linear feet. Two top plates plus one bottom plate is the standard (3 x length ft).

Each door adds 3 studs: two jack studs supporting the header and one cripple stud above the header.

16 OC is the standard and works with all standard drywall and sheathing. 24 OC saves lumber and reduces thermal bridging but is typically used with 2x6 studs and heavier sheathing.

Rounding up gives the number of bays, including any partial bay at the end of the wall. Adding 1 accounts for the stud at the far end of the wall - without it, the last bay would be open. This is the same reason a 10-foot fence with posts every 2 feet needs 6 posts, not 5.

Always add 5-10% when ordering. Cuts for diagonal bracing, damaged boards, and future repairs justify rounding up to the nearest bundle.

Headers are typically doubled 2x lumber. The header length shown is a planning estimate based on opening count - (doors + windows) x 3.5 ft, where 3.5 ft approximates a typical 3 ft rough opening plus 3 inches of bearing on each side. If your actual opening widths differ from 3 ft, size each header from its own rough opening plus 3 inches of bearing per side instead of using this estimate.