Construction
Deck Cost Calculator
Enter your deck dimensions and material to estimate surface area, the linear feet of decking and number of 16-foot boards to order, joist count at 16" on center, and an installed cost range.
Quick answer: A new deck costs roughly $15–$80 per square foot installed — about $4,800–$25,600 for a 320 sq ft deck — depending on pressure-treated, composite, or hardwood material.
- Decking boards (linear ft, incl. waste)803 ft
- 16-ft boards to order51
- Joists at 16″ on center13
- Waste allowance (15%)included above
- Estimated installed cost$9,600 – $19,200
Board counts assume 5½″ face-width decking in 16-ft lengths and 16″ joist spacing. Cost is a directional installed range — framing height, railings, stairs, footing depth, and demolition all move the real number.
How it works
1. Measure length × width
Multiply to get surface area in square feet. Add waste for the cutting pattern: 10% for a simple rectangle, up to 22% for picture-frame borders and curves.
2. Count boards and joists
Decking is estimated from 5½" face-width boards in 16-ft lengths. Joists run 16" on center, so the count is roughly the deck length divided by 1.33, plus one.
3. Apply a material price
Cost per square foot ranges from ~$15 for pressure-treated pine to ~$80 for tropical hardwood, installed. Railings, stairs, and footing depth move the real number.
Frequently asked questions
How much does a deck cost to build?
Installed decks run roughly $15–$80 per square foot depending on material — pressure-treated is the budget end, composite and PVC are mid-range, and tropical hardwood is premium. A 320 sq ft composite deck typically lands in the $10,000–$19,000 range.
How many deck boards do I need?
Divide the deck area by the coverage of one board (a 5½" board covers about 0.46 sq ft per foot of length), then add 10–22% for waste. The calculator converts this into 16-foot boards to order.
What's the best decking material?
Composite and PVC cost more upfront but need almost no maintenance; pressure-treated pine is cheapest but needs sealing. Cedar and tropical hardwood sit in between on price and upkeep.