HomeMaterialBaseHomeMaterialBase

Lumber calculator

Framing shopping lists are piece counts first — studs on 16 in centers, joists on a span — then board feet if the yard wants bf. This page is the piece-count ticket with an optional bf rollup. Enter wall length or floor L×W, spacing, waste for cutoffs, and stock sizes. Not engineered-lumber design and not a permit set.

ft
in
ft
Corners / openings
in
For bf
in
For bf
10%
0510152025

+10% so you don't come up short

ORDER ESTIMATELUMBER
Pieces to buy19
Linear ft (stock)152 ft
Board feet66.5
Waste10%
How it calculates
pieces = floor(run×12 ÷ spacing) + 1 + extras + plates; order = ceil(pieces × (1 + 10%)); optional bf = T×W×stock×pieces ÷ 12.

Estimate only — not a contractor bid. Confirm bag yields and local codes before you pour or order.

When to use

Partition wall stud list; simple joist count for a shed floor; converting a sketch into a big-box cart.

When not to

Trusses, LVL drops, or stamped beam calcs. Pure bf from random hardwood stock → board foot calculator. Deck boards by face width → deck board calculator.

Assumptions

Studs ≈ floor(length_in ÷ spacing_in) + 1 (plus extras you add for corners/openings). Joists similar along span. Waste default 10% on linear stock for cutoffs. Optional bf using T×W×L÷12 per piece. Plate lumber (top/bottom) counted separately when you enable plates.

Worked examples

Example 1

16 ft wall, studs @ 16 in o.c., waste 10% on extras
→ 16×12/16 + 1 = 13 studs before corners/fire blocks — add your extras

Corners and double studs at openings are easy to under-count.

Example 2

12×16 floor, joists @ 16 in along 16 ft span
→ joist count from width ÷ spacing + 1

Rim joists and blocking are separate lines.

How it calculates

Spacing layout to piece count, optional plates and board-foot rollup.

  1. Enter run length and o.c. spacing.
  2. Toggle plates; add extras for corners/openings.
  3. Optional T×W for bf; set waste; read pieces.
pieces = floor(run ÷ spacing) + 1 (+ openings/corners extras)
linear ft = pieces × stock_length
optional bf sum; apply waste on pieces as labeled

Common traps

  1. Spacing is o.c. — measure layout, not clear gap only.
  2. PT vs kiln-dried is species/treatment, not a different count formula.
  3. Headers and cripples — wall length math alone under-buys.
  4. Crown and reject rate — buy a couple extras on long spans.

Next tool

Board feet only → board foot calculator.

Deck framing → deck calculator.

Rafter length → rafter calculator.

FAQ

Wall length in inches ÷ spacing + 1, then add corners and openings.

Related

Estimate only — not a contractor bid or engineered takeoff. Confirm bag yields and local codes before you pour or order.