Deck Board Calculator
Boards Needed
29 boards
348 linear ft • 144 sq ft deck area • 10% waste included
Board Count
29
Linear Feet
348
Deck Screws
348
Est. Board Cost
$348 – $870
Tip: Choose board lengths that minimize waste. If your deck is 12 ft wide, use 12 ft boards to avoid splices. Leave 1/8″ gap between boards for drainage and expansion.
Disclaimer: Estimates are for budgeting purposes only. Actual costs vary by location, contractor, material availability, and project complexity. Always get professional quotes for exact pricing.
Deck Board Cost Breakdown
Pressure-Treated Board Costs by Length (5/4 × 6)
| Board Length | Cost per Board | Cost per LF | Coverage (sq ft) |
|---|---|---|---|
| 8 ft | $8 – $14 | $1.00 – $1.75 | 3.67 sq ft |
| 10 ft | $10 – $18 | $1.00 – $1.80 | 4.58 sq ft |
| 12 ft | $14 – $24 | $1.17 – $2.00 | 5.50 sq ft |
| 16 ft | $18 – $32 | $1.13 – $2.00 | 7.33 sq ft |
| 20 ft | $25 – $45 | $1.25 – $2.25 | 9.17 sq ft |
* Coverage based on 5.5″ actual board width with 1/8″ gap.
Decking Material Comparison
| Material | Cost / LF | Lifespan | Maintenance |
|---|---|---|---|
| Pressure-Treated | $1.25 – $2.50 | 15 – 25 yrs | Annual stain/seal |
| Cedar | $2.00 – $4.00 | 15 – 20 yrs | Annual seal, biannual stain |
| Composite (Standard) | $2.50 – $4.00 | 25 – 40 yrs | Occasional cleaning |
| Composite (Premium) | $4.00 – $7.00 | 30 – 50 yrs | Minimal |
| PVC / Cellular | $5.00 – $9.00 | 30 – 50 yrs | Minimal |
* Costs are material only. Professional installation adds $8–$22/sq ft.
How We Calculate
Our deck board calculator estimates the number of boards, total linear feet, screws needed, and material cost based on your deck dimensions, board width, board length, gap spacing, and material type.
How the math works: Boards across (rows) = deck width ÷ (board width + gap). Boards along = deck length ÷ board length (rounded up). Total boards = rows × boards along. Total linear feet = total boards × board length. Screws = 2 per joist crossing per board. All results include a 10% default waste factor, adjustable by the user.
Board Count Formula
Step 1: Convert deck width to inches. Divide by (board width in inches + gap in inches) to get the number of rows. Round up to the nearest whole board. Step 2: If deck length exceeds board length, calculate how many boards are needed end-to-end per row. Step 3: Multiply rows × boards per row to get total boards. Step 4: Multiply by (1 + waste factor).
Screw & Fastener Estimates
For face-screwed boards: 2 screws at each joist crossing. At 16″ OC joist spacing, a 16 ft board crosses 13 joists = 26 screws per board. For hidden fastener systems: 1 clip per joist crossing per board. A 1 lb box of #8 × 2.5″ deck screws contains approximately 100–125 screws. Stainless steel screws are recommended for cedar and composite to prevent staining.
Material Cost Ranges
Pressure-treated: $1.25–$2.50/LF. Cedar: $2.00–$4.00/LF. Composite (standard): $2.50–$4.00/LF. Composite (premium): $4.00–$7.00/LF. PVC: $5.00–$9.00/LF. Our calculator uses mid-range pricing by default. Actual costs vary by brand, retailer, and region.
Waste Factor
Default 10% covers cuts at the ends of rows, butt joint alignment, and board defects. Increase to 15% for diagonal patterns, angled deck shapes, or picture-frame borders. Reduce to 5% for simple rectangular decks where board length matches deck length exactly (no butt joints needed).
Data Sources
Material costs are compiled from Home Depot, Lowe’s, and specialty lumber suppliers. Composite pricing reflects Trex, TimberTech, and Fiberon product lines. Fastener counts follow manufacturer installation guides. We review pricing quarterly. Costs vary by region and availability.
Last updated: 2026-02-08
Frequently Asked Questions
How many deck boards do I need? +
Divide your deck width by the board width plus a 1/8″–1/4″ gap to get the number of rows, then multiply by the number of boards along the length. For example, a 12 × 16 ft deck using 5.5″ wide boards with 1/8″ gaps: 12 ft ÷ (5.625″ / 12) = ~25.6 rows. At 16 ft board length, that’s 26 boards. Add 10% waste = 29 boards total.
What are the standard deck board sizes? +
Standard deck boards are 5/4″ × 6″ (actual: 1″ × 5.5″) or 2″ × 6″ (actual: 1.5″ × 5.5″). Common lengths are 8, 10, 12, 16, and 20 ft. Composite boards are typically 1″ × 5.5″ or 1″ × 7.25″ in 12, 16, or 20 ft lengths. Wider boards (7.25″) mean fewer boards needed but cost more per board.
What gap should I leave between deck boards? +
Leave 1/8″ gap between pressure-treated boards after they dry (install tight when wet — they shrink). For composite and PVC boards, follow the manufacturer’s spacing guide: typically 3/16″–1/4″ for thermal expansion. Use a 16d nail or a dedicated spacer tool to maintain consistent gaps. End-to-end joints need 1/8″–3/16″ gaps.
Is pressure-treated wood or composite decking better? +
Pressure-treated (PT) lumber costs $2–$4/sq ft and lasts 15–25 years with annual staining. Composite decking costs $4–$10/sq ft but lasts 25–50 years with virtually no maintenance. PT is better for tight budgets; composite saves money over 15+ years. Composite also resists rot, insects, and fading. PVC decking ($6–$12/sq ft) is the most durable but costliest option.
How many screws do I need per deck board? +
Use 2 screws per joist crossing. At 16″ joist spacing on a 16 ft board, that’s about 24 screws per board. For the entire deck, estimate 350–400 screws per 100 sq ft. Use #8 or #10 × 2.5″–3″ stainless steel or coated deck screws. Hidden fastener systems use 1 clip per joist per board — roughly 175–200 clips per 100 sq ft.
How much waste should I plan for deck boards? +
Plan for 10% waste on straightforward rectangular decks. Add 15% for diagonal board patterns. Add 15–20% for complex shapes, angles, or octagonal decks. Use 5% if the deck dimensions divide evenly into board lengths with minimal cutting. Butt joints (boards meeting end-to-end) generate more waste — stagger joints across joists for structural integrity.
Should I run deck boards parallel or perpendicular to the house? +
Most deck boards run perpendicular to the house (parallel to the joists direction would require blocking). Perpendicular boards are structurally standard and look traditional. Diagonal patterns (45°) add visual interest but use 15% more material and require more cuts. Picture-frame borders use a perimeter board running in the opposite direction for a finished look.
How much does deck board material cost? +
Pressure-treated 5/4×6 boards cost $1.25–$2.50/LF ($8–$20 per 8 ft board). Cedar costs $2–$4/LF. Basic composite (Trex Enhance) costs $2.50–$4/LF. Premium composite (Trex Transcend, TimberTech) costs $4–$7/LF. PVC (Azek, TimberTech Advanced) costs $5–$9/LF. For a 12 × 16 ft deck, boards alone cost $350–$1,700+ depending on material.
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