Understanding Board Foot Pricing for Tropical Hardwood Lumber

Board Foot Pricing: Getting the Math Right

Unlike dimensional softwood lumber (which is priced by the linear foot or piece), tropical hardwood is typically priced by the board foot (BF) — a unit of volume that equals 144 cubic inches, or a piece of wood 12" long x 12" wide x 1" thick. Understanding board foot calculations is essential for accurate estimating and fair price comparison.

The Board Foot Formula

BF = (Thickness in inches × Width in inches × Length in feet) ÷ 12

For a standard 5/4 x 6 x 8' deck board: BF = (1.25 × 6 × 8) ÷ 12 = 5.0 BF per board

For a 1 x 6 x 8' board: BF = (1 × 6 × 8) ÷ 12 = 4.0 BF per board

Nominal vs. Actual Dimensions

Important: Board foot calculations use nominal dimensions (the size before surfacing), not actual dimensions. A 5/4 x 6 board that actually measures 1" x 5-1/2" after surfacing is still calculated as 1.25 x 6 for board foot pricing. This is industry standard and applies universally.

Converting Board Feet to Square Feet

To determine how many board feet you need for a given deck area:

1. Calculate the deck area in square feet
2. Divide by the coverage factor for your board width (accounting for gaps)

For 5/4 x 6 decking with 1/8" gaps:

• Each board covers approximately 5.625" of width (5.5" board + 0.125" gap)
• Coverage per board foot = 0.469 sq ft
• Or approximately 2.13 BF per square foot of deck surface

Rule of Thumb: For 5/4 x 6 tropical hardwood decking, multiply your deck square footage by 2.2 to get the approximate board feet needed (before waste factor).

Waste Factor

Always add a waste factor to your board foot calculation:

• Simple rectangular deck: 10–12%
• Moderate complexity (angles, stairs): 15%
• Complex (curves, multiple levels, herringbone): 18–20%

Comparing Supplier Quotes

When comparing prices between suppliers, ensure you're comparing apples to apples:

Per Board Foot: The most common pricing unit. Compare the $/BF directly, but verify that both suppliers are quoting the same grade (Select vs. Standard), species, and moisture content.

Per Linear Foot: Some suppliers quote per linear foot for specific profiles. To convert: multiply $/LF by 12, then divide by (thickness in inches × width in inches) to get $/BF.

Per Square Foot: Occasionally used for consumer-facing quotes. To convert: divide $/SF by the coverage factor (approximately 2.13 BF/SF for 5/4x6) to get $/BF.

Price Benchmarks (2025)

As of early 2025, typical $/BF pricing for kiln-dried, S4S tropical hardwood decking:

| Species | Standard Grade | Select Grade | |---|---|---| | Ipe | $8.00–$11.00 | $10.00–$14.00 | | Cumaru | $5.50–$8.00 | $7.00–$10.00 | | Garapa | $4.50–$6.50 | $6.00–$8.50 | | Tigerwood | $5.00–$7.00 | $6.50–$9.00 |

Prices vary by region, quantity, and market conditions.