Deck cost per square foot: framing, decking and the hidden line items
Square footage sets your decking order. Joist spacing, beam spans and footing count set almost everything else.
6 min read · Estimates only — not a quote
Two budgets in one project
A deck is a framing budget plus a surface budget. The surface scales cleanly with area. The framing scales with span: tighter joist spacing for a given board thickness, longer beam spans needing bigger members, and more footings as the frame grows.
That is why two decks of identical square footage can differ by hundreds of dollars — one is a low 12 ft x 12 ft platform, the other is elevated with longer spans and stair framing.
- Joists: area and spacing driven; 12 in on centre is roughly 33% more joists than 16 in.
- Beams and posts: driven by span, not area.
- Footings: concrete volume per hole times hole count.
- Fasteners and hangers: scale with joist and connection count, and are routinely underestimated.
Deck material estimates by state
Same deck, different regional material index. These are DIY material estimates only — labor is excluded.
| State | Low | Typical | High | vs. national |
|---|---|---|---|---|
| Texas | $2,645 | $3,112 | $4,201 | -3% |
| California | $3,217 | $3,785 | $5,110 | +18% |
| Florida | $2,754 | $3,240 | $4,374 | +1% |
| New York | $3,136 | $3,689 | $4,980 | +15% |
| Pennsylvania | $2,836 | $3,336 | $4,504 | +4% |
| Illinois | $2,890 | $3,400 | $4,590 | +6% |
| Ohio | $2,618 | $3,080 | $4,158 | -4% |
| Georgia | $2,618 | $3,080 | $4,158 | -4% |
Check your spans before you buy lumber
Undersized joists or over-long beam spans are the most expensive mistake in a deck build, because the fix is a rebuild. Our span check flags joist and beam spans that fall outside common IRC-style span tables before you order material. It is guidance, not an engineering stamp — for elevated or unusual decks, have a local professional review the frame and confirm permit requirements.
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Price my deckFrequently asked questions
Decking surface choice and framing span. Surface material scales with area; framing scales with span and height, which is why elevated decks cost far more per square foot than ground-level platforms.
Very often yes, especially above a height threshold or when attached to the house. Thresholds are set locally — check the permit lookup for your city and county before you build.