How the cost estimate works
The calculator first works out exactly which boards to buy — rows, seams on joists, a cut plan and your extra allowance. Then it prices that purchase:
- Per linear foot: total length purchased × your price per foot.
- Per board: number of boards of each length × your price for that length.
- Per square foot: the coverage you buy (deck area scaled up for offcuts and allowance) × your price.
The breakdown separates the cost of boards you'll install from the cost of waste, so you can see what a tighter layout or a different board length would save.
Example: when the longest board isn't the cheapest
Take a 20 × 14 ft deck with boards running along the 20 ft side. Suppose — as an illustration — a supplier charges $30 for a 12-ft board, $40 for a 16-ft board and $56 for a 20-ft board, so the 20-footer costs more per foot.
- Buying all 20-ft boards: 30 boards, no seams, $1,680 before the allowance.
- The optimizer's pick: all 16-ft boards — 40 × 16-ft — with 30 staggered seams for $1,600.
That's $80 less, in exchange for some butt seams and doubled joists. Whether that trade is worth it is your call — the “Which board lengths to buy” table lays out both.
Typical board-material price ranges
As a sanity check, 2025–26 cost guides put deck board material (per square foot of deck) roughly at:
| Material | Board material, per sq ft |
|---|---|
| Pressure-treated pine | about $2–8 |
| Cedar | about $4–12 |
| Composite | about $5–18 |
| PVC | about $8–20 |
Sources: HomeGuide, Ergeon, DecksDirect. These ranges are wide and exclude framing, fasteners and labor. Use real local prices for your estimate.
Ways to lower your decking cost
- Compare board lengths. Enter per-board prices; long boards save seams but sometimes cost more per foot.
- Try both directions. Rotating the boards can change how well your lengths fit the deck.
- Tune the gap. A slightly different gap can drop a whole row — check with the spacing calculator.
- Use offcuts. The cut plan flags offcuts 2 ft or longer, which work for stair treads or blocking.
Frequently asked questions
How much does it cost to build a deck per square foot?
Published 2026 national averages put a professionally built deck at about $30 to $60 per sq ft (Angi) or $25 to $50 per sq ft (HomeGuide). Pressure-treated wood sits at the low end, composite and PVC at the high end, and raised or multi-level decks cost more. Local prices can be well above or below these ranges.
How do I calculate a deck price?
Price it line by line. Get the board count by length from the deck board calculator and multiply by your supplier's per-board prices (this page does that for you). Then add framing lumber, footings and concrete, fasteners, stairs, railings, finish, the permit and labor if you're hiring. The deck cost breakdown walks through every line, and the framing, railing and stair calculators give the quantities.
How much is a 500 sq ft deck?
At Ergeon's 2026 installed ranges ($25 to $40 per sq ft for treated wood, $35 to $55 for mid-grade composite), a 500 sq ft deck comes to about $12,500 to $20,000 in pressure-treated wood or $17,500 to $27,500 in mid-grade composite, before railings, stairs or demolition.
How much does a 1000 sq ft deck cost?
Using the same Ergeon installed ranges, 1000 sq ft works out to about $25,000 to $40,000 in pressure-treated wood or $35,000 to $55,000 in mid-grade composite. A deck this size needs more beams, posts, footings and usually more railing, and some areas ask for engineered plans on large decks, so check with your building department and get several itemized quotes.
How much does it cost to pay someone to build a deck?
Labor alone typically runs about $11 to $22 per sq ft (HomeGuide), and Angi gives a wider $8 to $40 per sq ft, with the top end for raised, complex or hard-to-reach decks. On HomeGuide's figures, labor is a little under half of a typical deck's total cost.
What is the cheapest deck to build?
A simple, low, rectangular deck in pressure-treated pine. Treated boards are the least expensive decking material at about $2 to $3 per sq ft for materials, against $5 to $13 for composite. Keeping the deck close to the ground avoids railings and long stairs, and choosing dimensions that match standard board lengths keeps waste down — the calculator above shows the cheapest mix of lengths for your size.
What is the most expensive part of a deck?
Labor is usually the largest single cost when you hire a builder. Among materials, the decking surface costs the most on composite and PVC decks, while on raised decks the railing can rival or beat the boards. Framing and footings cost about the same whatever decking you choose. See the deck cost breakdown for each line.
How much is a 20 ft decking board?
Prices vary widely by material, brand and region, so check your supplier. As a rough guide, a 20-ft, 5-1/2" board covers about 9.2 sq ft of deck. At Ergeon's materials ranges that works out to roughly $18 to $28 for pressure-treated pine and $46 to $119 for composite. Enter your real per-board prices above to see which lengths are cheapest for your deck.
How much does it cost to replace a deck board?
For a DIY replacement you pay for the board and a few screws. As a rough guide from Ergeon's materials ranges, a 20-ft board is about $18 to $28 in pressure-treated pine and $46 to $119 in composite. If you hire someone, labor is the bigger part, and small repairs are often priced with a minimum visit charge, so replacing several boards in one visit costs less per board. Damaged joists underneath add to the job.
Does this calculator use live store prices?
No. Prices change by region, store and week, so the calculator only uses the prices you enter. Grab them from your lumberyard, a store website or a contractor quote.
How do I convert a price per board into a price per linear foot?
Divide the board price by its length in feet. A $40 16-ft board is $2.50 per linear foot. If your supplier prices each length differently, choose “Per board” and enter each one — the optimizer will then pick the cheapest mix of lengths.
What does a square-foot price mean for decking?
Some suppliers quote decking per square foot of deck it covers. The calculator prices the coverage you actually buy, including offcuts and your allowance, not just the deck area — otherwise the estimate would come in low.
What else should I budget for beyond deck boards?
Fasteners or hidden clips, fascia and trim, stair treads, railing, and framing lumber if you’re building new. Add a lump sum under “Other materials” to see it in the total. For new builds, framing, footings and labor are usually a large share of the total cost.