Board Foot (FBM) Lumber Calculator
Calculate board feet (FBM) for hardwood and softwood lumber volume and total pricing for woodworking and timber supply.
Enter Your Dimensions
US • ftHow We Calculated This
• Surfaced 4 sides (S4S) dimensional lumber has smaller actual dimensions (a 2x4 is actually 1.5" × 3.5").
Formula & Volumetric Method
1 Board Foot = 1" thick × 12" wide × 12" long (144 cubic inches). Formula: (Thickness" × Width" × Length') / 12.
Calculations are performed strictly using standard civil engineering constants. Volumetric outputs are normalized to true compaction rates, ensuring purchased quantities match jobsite yields.
Jobsite Engineering Guidelines
- Hardwood lumber is sold by board foot volume (BF or FBM) based on rough-sawn dimensional thickness (e.g. 4/4 is 1", 8/4 is 2").
Frequently Asked Questions
How accurate is the Board Foot (FBM) Lumber Calculator for ordering materials?
Our calculations match standard store packaging sizes in the US, Canada, UK, and Australia. We include a safety waste buffer (default 8% to 12%) so you do not run short due to uneven ground or spillage.
Why should I add extra for waste when ordering?
Uneven ground, cutting scrap, and leftover mix in the wheelbarrow or mixer drum consume an extra 5% to 15% of material. Ordering only the exact measurement usually leaves you short, which can lead to expensive extra delivery fees.
Does this calculator support both Imperial and Metric units?
Yes. You can switch between US Customary (feet, inches, cubic yards, pounds), Canadian units, UK metric, and Australian standards using the region selector in the header or the unit dropdown on each input.