Deck Calculator
Estimate deck boards, framing, and total project cost
Length of deck
Width of deck
Nominal width
16" standard, 12" composite
Deck Area
—
sq ft
Deck Boards
—
boards
Joists Needed
—
joists
Footings Needed
—
footings
Estimated Cost
—
USD
How to Use This Calculator
A well-planned deck starts with accurate material estimates. Our calculator helps you determine boards, joists, and footings.
- Measure deck length and width
- Choose decking material
- Select joist spacing
- Enter specifications
- Add 10-15% waste
AI Insights
Smart analysis for your project
Smart Estimates
Our AI cross-references material costs, regional pricing, and project complexity for more accurate estimates.
Waste Optimization
AI-calculated waste factors based on project type, not flat percentages. Saves 5-15% on material costs.
Best Practices
Recommendations derived from building codes, contractor data, and thousands of completed projects.
Calculation Formula
Area = L x W
Boards = ((W x 12) / Board width) x (L + 1)
Joists = (L x 12 / Joist spacing) + 1
Frequently Asked Questions
How much does a deck cost?
Pressure-treated wood: $15-$30/sq ft. Composite: $30-$45/sq ft. A 16x12 deck costs $2,880-$7,200.
What spacing should deck joists be?
Standard: 16" OC for wood. 12" OC for composite. 24" only for 2x6 boards.