Lumber calculator

Frame a wall without guessing. Enter the wall size and spacing to get studs, plates, total board feet and an optional cost.

Studs: –
Stud length: –
Plates (16 ft boards): –
Board feet: –
Lumber cost: –

What to buy

How wall lumber is counted

A framed wall is studs on a fixed spacing between a bottom plate and a double top plate. Corners and openings need extra studs, so the calculator adds 2 for each.

Studs = wall length (in) ÷ spacing, rounded up, + 1, + 2 per corner, + 2 per opening

Plates = wall length × 3, in linear feet

Worked example

A 16 foot wall, 8 feet high, studs at 16 inches with one door: 192 ÷ 16 = 12, plus 1 is 13 studs, plus 2 for the door is 15 studs cut to 91 1/2 inches. Plates are 48 linear feet, three 16 foot boards.

What this leaves out

Headers over doors and windows. Size them for the span and the load above.
Cripple studs above and below windows.
Blocking and fire blocking where your code asks for it.

Questions people ask

How many studs do I need for a wall?

For studs 16 inches on center, multiply the wall length in feet by 0.75 and add 1. Then add 2 studs for each corner and 2 for each door or window opening for the king and jack studs.

How long are studs for an 8 foot wall?

An 8 foot wall with one bottom plate and a double top plate needs studs 91 1/2 inches long. Precut 92 5/8 inch studs are sold so the finished ceiling height clears 8 feet with drywall.

How many plates does a wall need?

One bottom plate and two top plates, so three times the wall length in linear feet.

Should I use 2x4 or 2x6 studs?

2x4 is standard for interior walls. Exterior walls often use 2x6 for more insulation depth, usually at 24 inches on center.