Calculate lumber board feet (FBM), linear feet, piece pricing, timber volume, and wood species weight across softwoods and hardwoods with nominal and actual dimensions.
A board foot is a specialized volume unit equal to a 1-inch thick, 12-inch wide, 12-inch long piece of wood (144 cubic inches).
The standard commercial formula is:
BF = (Nominal Thickness x Nominal Width x Length in feet) / 12.
Framing lumber is referred to by its rough green dimension before kiln-drying and factory planing. A 2x4 is actually 1.5" x 3.5"; a 2x8 is 1.5" x 7.25"; and a 4x4 is 3.5" x 3.5". Board footage is always calculated using the nominal numbers.
Softwood lumber (framing studs, joists, and rafters) is sold by the individual stick piece at retail stores. Hardwoods (oak, cherry, walnut) are sold exclusively by the board foot, categorized by quarter-inch thickness designations (4/4, 5/4, 6/4, 8/4).
Kiln-dried softwoods average 2.0 to 2.8 lbs per board foot. Wet, freshly pressure-treated pine lumber weighs nearly double (up to 4.0 to 4.2 lbs/BF). Check your pickup truck or trailer payload rating before loading multiple bundles.
| Species Name | Classification | Density (lbs/cu ft) | Weight per Board Foot | Primary Engineering Use |
|---|---|---|---|---|
| Douglas Fir / Larch | Softwood (Structural) | 34 lbs/cu ft | 2.83 lbs/BF | Floor joists, roof rafters, structural headers |
| Southern Yellow Pine (KD) | Softwood (Heavy) | 32 lbs/cu ft | 2.67 lbs/BF | Trusses, framing, subflooring |
| Spruce-Pine-Fir (SPF) | Softwood (Light) | 28 lbs/cu ft | 2.33 lbs/BF | Standard wall studs and interior partition plates |
| Red Oak | Hardwood (Dense) | 45 lbs/cu ft | 3.75 lbs/BF | Hardwood flooring, furniture, architectural trim |
| Western Red Cedar | Softwood (Rot-Resistant) | 23 lbs/cu ft | 1.92 lbs/BF | Outdoor decks, pergolas, siding, shingles |
| Pressure-Treated Pine (Wet) | Treated Softwood | 48 lbs/cu ft | 4.00 lbs/BF | Ground-contact deck posts, sill plates, landscaping |
Hardwood sawmills and commercial suppliers quote lumber in board feet (144 cubic inches of wood), while retail home centers quote per linear foot. Confusing these two distinct metrics leads to severe budget and procurement misunderstandings.
A surfaced 2x4 board actually measures 1.5" x 3.5", but commercial board footage is legally measured using nominal rough dimensions. Calculating board feet with actual surfaced dimensions produces incorrect sawmill invoice reconciliations.
Purchasing rough-sawn hardwood lumber (4/4, 8/4, 12/4) requires jointing and planing, which reduces stock thickness by 1/8" to 1/4". Factoring accurate waste allowances ensures sufficient rough stock is ordered for finished cabinetry.
Framing floors, roof rafters, and timber trusses requires combining dozens of individual pieces across multiple lengths. This calculator provides instant single-piece board footage, linear footage, and batch pricing per thousand board feet (MBF).
Computes exact Board Feet (FBM) using standard industry formula: (Thickness × Width × Length in ft) / 12.
Pre-configured nominal sizes from 1x2 through 6x12, with full support for custom hardwood and timber dimensions.
Instant output in Board Feet, total Linear Feet, Cubic Feet, and Cubic Meters for domestic and export freight.
Calculates total costs seamlessly whether priced per single board, per linear foot, or per thousand board feet (MBF).
