Board Foot Calculator
The lumber math staple. Convert dimensioned lumber (thickness × width × length × quantity) to board feet, the standard volume unit for hardwood, cedar, and tropical lumber pricing. 13 species — pressure-treated SYP, cedar Western Red, redwood, Douglas fir, hemlock, white oak, mahogany, IPE, cumaru, tigerwood, garapa, massaranduba + more. Multi-row mode rolls up a full deck BoM (joists + decking + posts) with mixed species. Weight (lbs) + cost range + heavy-load delivery advisory.
Inputs
Advisories
PT lumber in order — fastener advisory
IRC R317 + ICC-ES ESRModern PT chemistry (ACQ, MCA, CA-C, CuN) is corrosive to coated steel. Use hot-dip galvanized G185 or stainless 305 fasteners for all PT-to-PT connections. Standard coated screws will fail within 3-7 years.
Per-row breakdown
BF = (thickness_in × width_in × length_ft × quantity) ÷ 12Always use nominal dimensions — a "2×10" is 2″ × 10″ nominal, not 1.5″ × 9.25″ actual.Need a full deck cost?
The Deck Cost Calculator gives you a complete project budget — materials, labor, permits, contingency — across 5 finish tiers.
Board feet uses nominal dimensions per ANSI/NIST PS 20. Cost ranges are 2026-Q1 national-median retail; expect ±20% variance from your local lumber yard. Weight uses kiln-dried density values from ASTM D2555. DeckMath is not affiliated with any lumber supplier.
How to use
How to use the board-foot calculator in 5 steps.
- 1
Pick single-row or multi-row mode
Single-row is the quickest answer for one lumber size ("how many BF in 12 pieces of 2×10 × 12 ft?"). Multi-row is the deck-BoM mode — up to 8 rows, each with its own thickness × width × length × qty + optional row-specific species + label (Joists / Decking / Beam / Posts etc).
- 2
Choose a default species
13 species across softwood, cedar, hardwood, and tropical. Default species applies to every row unless you override a specific row. Density (lbs/cf) drives weight; retail $/bf range drives cost. Heavy tropicals (IPE, Massaranduba) at 64-69 lbs/cf weigh 2-3× softwoods.
- 3
Enter dimensions per row
Thickness (in) × Width (in) × Length (ft) × Quantity (pieces). Use nominal dimensions (a "2×10" is nominally 2″ × 10″ — the calculator uses these for BF math, not the actual 1.5″ × 9.25″ S2S dimensions). Common drop-downs cover 1, 1.25, 1.5, 2, 3, 4, 6 thickness and 2-12 width.
- 4
Toggle weight + cost
Weight uses species density × volume; cost uses the species' national-median $/bf range × your state's regional multiplier. Turn off either if you just want pure BF math.
- 5
Read your BoM
Per-row breakdown shows BF + LF + weight + cost range. Totals roll up across all rows. Heavy-load flag (≥2000 lbs) advises delivery vs trailer haul. Save link, export PDF, embed.
How we calculate
How DeckMath calculates this — IRC 2021 sources.
The Board Foot Calculator converts dimensioned lumber to board feet — the standard volume unit for hardwood, cedar, and tropical lumber pricing. Enter thickness, width, length, and quantity; pick a species, and the calculator returns total board feet, total linear feet, lumber weight (lbs), and cost across a 2026-Q1 retail price range. Multi-row mode lets you build a full deck BoM in one calc — joists at 2×10 × 12 ft × 12 pcs + decking at 5/4×6 × 16 ft × 20 pcs + posts at 6×6 × 10 ft × 4 pcs — and roll up board feet + weight + cost across mixed species. 13 species covered: pressure-treated SYP, cedar (Western Red), redwood, Douglas fir, hemlock, white oak, mahogany, IPE, cumaru, tigerwood, garapa, massaranduba, untreated SYP.
IRC references
- ANSI/NIST PS 20 — American Softwood Lumber Standard
- AWC NDS — National Design Specification for Wood Construction (board foot used for material orders + structural calcs)
- AWC DCA-6 — Prescriptive Residential Wood Deck Construction Guide (PT lumber sizing)
- ASTM D2555 — Establishing Clear Wood Strength Values (density references)
Density values from ASTM D2555 kiln-dried hardwood/softwood reference tables. Retail $/bf ranges reflect 2026-Q1 national-median pricing at common grades (PT #2, Cedar Select Tight Knot, Hardwood FAS). Regional multiplier uses RSMeans 2026-Q1 residential index. Always use nominal lumber dimensions per ANSI/NIST PS 20.
The standard board foot is 144 cubic inches of nominal wood (1″ × 12″ × 12″ = 144 in³). The formula expresses this as the wood volume in cubic feet × 12. Always use NOMINAL dimensions (the "2×10" not the actual 1.5″ × 9.25″).
Total linear feet across all pieces of a given dimension. Useful for ordering — lumber yards quote per-LF for many softwoods and decking species. Different from BF: a 2×10 × 12 ft is 12 LF but 20 BF.
Volume in cubic feet = (thickness_in × width_in × length_ft × qty) ÷ 144. Then weight = volume × species density. PT SYP 36 lbs/cf, Cedar 23, IPE 69, etc. Used for delivery + trailer planning.
$/bf is the national-median retail range for that species at the typical grade (PT #2, Cedar Select Tight Knot, Hardwood FAS). Region multiplier: Northeast 1.20×, Midwest 1.00×, South 0.92×, West 1.15×, Mountain 0.98×.
Useful when converting to other units. 1 BF = 1/12 cubic foot. 100 BF of any species ≈ 8.33 cubic feet of wood.
Save your plan
Don’t lose this estimate.
Your inputs are preserved in the URL — email it to yourself or copy the link so you can compare with contractor bids later. No account needed.
Get matched
Want 2–3 free quotes for this exact deck?
We'll send your plan to vetted local builders. Free, no obligation.
People also ask
Board-foot questions, answered.
A board foot is a unit of lumber volume equal to 144 cubic inches — typically a 1-inch-thick board that's 12 inches wide and 12 inches long. The formula is BF = (thickness_in × width_in × length_ft × quantity) ÷ 12. Used industry-wide for hardwood, cedar, and tropical lumber pricing. A single 2×10 × 12 ft piece equals 20 board feet ((2 × 10 × 12 × 1) ÷ 12).
Linear feet (LF) measures just the length of the board — a 2×10 × 12 ft is 12 LF regardless of cross-section. Board feet (BF) measures the volume — same 2×10 × 12 ft is 20 BF. Pressure-treated framing lumber is usually priced per linear foot at the box store ($X.XX per 8-ft 2×10); hardwood and tropical lumber is priced per board foot from specialty suppliers ($Y.YY per BF). The calculator gives you both numbers.
Always nominal. A "2×10" is sold and priced as a 2-inch by 10-inch board even though the surfaced (S2S) actual dimension is 1.5″ × 9.25″. Board foot math always uses nominal dimensions — that's the industry standard. If you used actual dimensions you'd undercount your BF by roughly 28%.
Depends heavily on species. A 16×20 ft pressure-treated deck (joists 2×10 × 12 ft × 14 pcs + decking 5/4×6 × 16 ft × 28 pcs + posts 6×6 × 10 ft × 6 pcs ≈ 540 BF) weighs about 1620 lbs in PT (36 lbs/cf × 45 cf). The same deck in IPE weighs 3100 lbs (69 lbs/cf). For IPE: order delivery, don't trailer-haul. For PT: a 1500-lb load is manageable in a single F-150 bed.
Three reasons: (1) growing region + import duties (tropicals like IPE ship from Brazil with export tariffs); (2) density — heavier wood costs more to harvest, mill, and ship; (3) durability — naturally rot-resistant species (cedar, redwood, tropicals) command a premium because they outlast PT in outdoor use. PT SYP at $1.20-2.40/bf is the budget option; IPE at $8.50-14/bf is 5-7× the price but lasts 3× longer with proper maintenance.
Pressure-treated SYP at $1.20-2.40/bf is the cheapest by a wide margin. Untreated SYP is cheaper still but can't be used outdoors. PT lasts 15-25 years in service depending on grade + treatment + climate. If you want a non-PT look, Cedar Western Red at $3.50-5.50/bf is the next-cheapest naturally rot-resistant option.
The price ranges are 2026-Q1 retail national-median for typical grades (PT #2, Cedar Select Tight Knot, Hardwood FAS). Expect ±20% variance from your actual lumber yard quote. Specialty hardwood suppliers (J. Gibson McIlvain, IPE Woods USA) often beat box-store retail by 15-25% on tropical species when buying in volume (200+ BF orders).
Yes — board foot math is universal for any dimensional lumber. Use it for framing (2×4 wall studs, 2×10 floor joists), interior trim, furniture-grade hardwood orders, etc. The species catalog focuses on decking + framing species, but you can use "untreated SYP" or "white oak" or "mahogany" entries for any project where those species apply.
Regional lumber pricing varies up to 30% across the US. The calculator applies a region multiplier: Northeast 1.20×, West Coast 1.15×, Mountain 0.98×, Midwest 1.00× (baseline), South 0.92×. So a $1000 PT order in Pennsylvania (NE) costs ~$833 in Texas (South). The state input doesn't change board feet or weight — only the cost output.
The action bar generates a printable PDF with the per-row breakdown + totals + species notes. CSV export gives you a spreadsheet-ready file. Copy Link preserves all your inputs in the URL so a lumber supplier can open the same calculation. Embed code lets you put the calculator on a contractor blog or quote-tool page.
Embed this calculator
One line. Any site. Free.
Drop the snippet into your contractor site, blog, or marketing page. Theme matches the parent site automatically.
<!-- Board Foot Calculator — free embed by DeckMath --> <a href="https://deckmath.com/calculators/board-foot-calculator" data-deckmath-calc="board-foot-calculator" data-theme="auto">Free Board Foot Calculator by DeckMath</a> <script src="https://embed.deckmath.com/v1.js" async></script>
Plan the whole project, not just one number
The Deck Project Planner turns your dimensions into a complete material list, cost, 3D preview, and a PDF you can take to the lumber yard — all in one place.
Related