Lumber Calculator

Enter the wall length, the height and the spacing, add openings, and get the count and an optional cost.

Also converts between linear feet, board feet and cost per piece.

How to use the lumber calculator

Why use the Build Tally lumber calculator

Counting studs

The basic count is wall length divided by spacing, plus one for the end. Real walls need more: two or three studs at each corner depending on the corner detail, an extra stud where a partition meets, king and jack studs at every opening, and cripples above and below. A common shortcut is to take the basic count and add three studs per opening plus two per corner, which is what this calculator does. Sixteen inch on centre is standard in most residential framing; twenty-four inch appears in some walls and in advanced framing.

Plates, headers and what to buy

A standard wall has one bottom plate and a doubled top plate, so plate material is three times the wall length plus overlap at the joints. Bottom plates on concrete need to be pressure-treated. Headers over openings are sized by span and load and come from the code, not from an estimate. Buy plates in the longest lengths that fit your wall to reduce joints, and remember that studs are sold pre-cut to common wall heights, which is cheaper than cutting them from longer stock.

Grades, moisture and ordering extra

Framing lumber varies. Expect to reject some pieces for crowning, twisting or splits, so order roughly 5–10% extra rather than exactly the calculated count. Green or wet lumber will shrink and can twist as it dries, so store it flat and covered, and frame with the crown up consistently. Check whether your build calls for kiln-dried, and remember that nominal sizes are not actual — a 2×4 is 1.5 × 3.5 inches, which matters for both the calculation and the fit.

Read the guide: Deck Materials List: Working Out Boards, Joists, Posts and Fasteners