Construction & DIY

Stud Calculator

What this does

Count studs for a wall framed at 16 or 24 inches on center, with plate lumber and corner/opening guidance included.

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Calculator inputs

Using the stud calculator

  1. 01

    Enter wall length

    Measure the total run of the wall in feet, including any door or window openings within it.

  2. 02

    Choose spacing

    16″ OC suits most load-bearing and tiled walls; 24″ OC works for simple non-structural partitions and saves lumber.

  3. 03

    Add framing extras

    Use the note row: one backup stud per corner, jack and king stud pairs per opening, above the base count.

Why 16 inches won

Sixteen inches on center divides neatly into 48- and 96-inch sheet goods, letting sheathing land exactly on stud centers. Twenty-four-inch spacing halves stud count and passes code in many non-load applications; but check local rules before switching.

Openings eat studs quietly

A single window adds a header, two jack studs, two king studs and sill cripples; easily five members beyond open-wall spacing. Estimating walls by raw spacing alone is why framers buy 10–15% extra lumber.

Plates triple your linear footage

Every wall runs three plates: one on the floor and a double on top. The plate-lumber row captures that hidden demand, which on long walls rivals the studs themselves in board feet.

The math behind this calculator

Studs = ⌈ Wall length(ft) × 12 ÷ spacing(in) ⌉ + 1

Divide the wall’s length in inches by the on-center spacing to place studs, then add one for the closing end stud. The result covers king studs at wall ends; corners, doorways and window openings each demand additional jack, king and cripple studs noted separately below the result.

Assumptions & limitations

  • Single straight wall with studs at uniform on-center spacing.
  • Plates sized as one bottom plate plus a doubled top plate (three runs of lumber).
  • Load-bearing headers, corners and openings require extras beyond the computed count.

Worked example

Framing a 20-foot wall at 16″ on center places a stud every 16 inches: 240 ÷ 16 = 15, plus the end stud, for 16 studs; plus one extra at each corner and opening.

Frequently asked questions

How far apart are studs normally?
16 inches on center is the US default; 24 inches appears in energy-efficient advanced framing and some partitions.
Does the +1 stud really matter?
Yes; spacing alone places studs between the ends but leaves the final corner empty without the closing end stud.
Can I use this for a load-bearing wall?
For counting yes, but load-bearing walls also need engineered headers and possibly doubled studs; consult your plans or an engineer.
What height studs should I buy?
Pre-cut 92⅝" studs plus three 1½" plates produce exact 8-ft finished ceilings; the recommended-length row reflects your entered wall height.

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