Deck Cost Calculator
A deck needs its square footage divided by each board's coverage, plus joists spaced every 16 inches. Enter your deck size and board dimensions to estimate materials and an installed price range.
How to estimate decking boards
Find the deck area by multiplying length by width, then divide by the coverage of a single board — its face width (in feet) times its length. Add 10% for waste from cuts and the gaps between boards. Use the square footage calculator for multi-level or angled decks.
Joists and framing
Joists run across the width of the deck, spaced 16 inches on-center as standard, plus one extra closing joist. Closer 12-inch spacing stiffens the deck and is required for diagonal board patterns.
Deck cost range
The installed range here uses a common rule of thumb — labor and extras run two to four times the material cost. Pressure-treated pine is cheapest; composite and hardwood decking cost more but last longer. For perimeter fencing around the deck, see the fence calculator.
Frequently asked
How much does it cost to build a deck?
Most decks cost $30–$60 per square foot installed, so a 144 sq ft deck runs roughly $4,300–$8,600. Materials alone are about a quarter to a half of that.
How many deck boards do I need?
Divide the deck area by the coverage of one board (face width times length), then add 10% for waste. A 144 sq ft deck with 5.5 in × 16 ft boards needs about 22 boards.
How far apart should deck joists be?
Joists are typically spaced 16 inches on-center for residential decks, or 12 inches for diagonal decking or heavier loads.