Deck Calculator
Calculate decking boards, joists, posts, screws, and total cost for your deck project.
Deck Dimensions
Deck Area (sq ft)
--
Estimated Cost
--
Materials List
Deck Boards
--
Linear Feet
--
Joists
--
Posts (4x4)
--
Screws (lbs)
--
Beams
--
About This Calculator
This deck calculator estimates materials based on standard construction practices. Posts are spaced every 6-8 feet. Includes 10% waste factor for board cuts. Actual materials may vary based on design complexity, railing, stairs, and local building codes.
Adds your deck takeoff into the Construction Estimate Builder.
Saved Calculations
Deck Building Guide
Plan Your Layout
Measure the desired deck footprint. Most residential decks are 12-16 ft wide and 16-20 ft long. Check local setback requirements before finalizing the size.
Choose Your Material
Pressure-treated lumber is cheapest ($1.50-$2.50/ft). Composite decking ($3-$6/ft) lasts longer with less maintenance. Cedar/redwood ($3-$5/ft) is a natural premium option.
Understand Framing
Joists at 16" on center are standard. Use 12" spacing for composite boards or heavy loads. Posts should be set in concrete footings at least 42" deep (below frost line).
Decking Material Comparison
Pressure-Treated Pine
$1.50-$2.50/linear ft. Lifespan: 15-20 years. Requires annual staining/sealing. Most affordable option. Must dry 3-6 months before staining.
Composite (Trex, TimberTech)
$3-$6/linear ft. Lifespan: 25-50 years. Zero maintenance. Fade/stain resistant. Higher upfront cost pays for itself over time.
Cedar / Redwood
$3-$5/linear ft. Lifespan: 15-25 years. Naturally rot-resistant. Beautiful grain. Needs periodic sealing. Eco-friendly choice.
Frequently Asked Questions
Do I need a permit?
Most jurisdictions require a permit for decks over 30" above grade or larger than 200 sq ft. Always check local building codes before starting.
How deep should deck footings be?
Footings must extend below the frost line, typically 36-48" deep. In warmer climates, 12-18" may suffice. Check local codes for exact requirements.
What about railing costs?
Wood railing: $20-$35/linear ft installed. Composite: $30-$60/linear ft. Cable/metal: $60-$100+/linear ft. Required for decks 30"+ above grade.