Deck Calculator
Calculate deck materials including decking, framing, posts, and footings. Get complete material lists and cost estimates for your deck building project.
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How to Use This Calculator
Plan your deck build with accurate material estimates for framing, decking, and hardware:
- Enter the deck dimensions (length and width in feet).
- Select the decking material (pressure-treated wood, cedar, or composite).
- Choose joist spacing (16" for most applications, 12" for diagonal decking or heavy loads).
- Click 'Calculate' to see complete material lists including decking, framing, posts, and hardware.
Why This Matters
Deck projects involve many different materials - decking boards, joists, beams, posts, concrete for footings, and hundreds of fasteners. Missing any component can delay your project while you wait for materials. A comprehensive estimate helps you order everything at once, compare material costs between wood and composite options, and create an accurate budget before breaking ground.
- Get complete material lists in one calculation
- Compare costs between different decking materials
- Plan concrete footings with proper spacing
- Estimate fastener quantities (often overlooked)
- Budget accurately before starting construction
Worked Examples
Standard Deck
12' × 16' deck, 16" joist spacing, pressure-treated lumber.
Small Entry Deck
6' × 8' entry deck at back door, composite decking.
Large Entertainment Deck
16' × 24' deck for outdoor living space, cedar decking.
Common Mistakes to Avoid
- Forgetting concrete for post footings - each footing needs 1-2 bags of concrete minimum.
- Underestimating fastener quantities - you need hundreds of screws for a typical deck.
- Not accounting for the 5-10% waste factor on decking boards.
- Using wrong joist spacing for the decking type - composite often requires 12" spacing.
- Forgetting ledger board, flashing, and attachment hardware for house-attached decks.