Deck calculator
Estimate materials for your deck.
Enter your deck's length and width to get a decking board count, a rough footing count, and an estimated material cost.
Enter your deck
National average is $7–$15 per sq ft for decking material alone — framing, footings and railing add more.
Results
- Deck area
- —
- Decking boards
- —
- Footings (perimeter)
- —
- Estimated cost
- —
Footings are spaced along the deck's perimeter — confirm spacing and depth against your local frost line and code.
Estimates only — decking surface material and a rough footing count. Confirm framing, spacing and depth with your local code before building.
How it's calculated
Area ÷ board coverage, plus perimeter footings.
We find your deck's area, add your waste percentage, and divide by one board's coverage (its width × length) to get a board count, rounded up. Footings are estimated separately from your deck's perimeter, spaced at a standard interval — a starting point for planning, not a structural spec.
FAQ
Common questions
How many decking boards do I need?
We divide your deck's area (plus a waste allowance for cuts) by the coverage of a single board, based on its width and length. Boards typically run in one direction across the joists — the count assumes minimal seams.
How far apart should deck footings be?
We estimate footings spaced every 6 ft along your deck's perimeter as a starting point. Actual spacing depends on your beam size, joist span and local frost depth — confirm with your local code or an engineer before digging.
Does this include joists, beams and railing?
No — this estimates decking boards (the surface material) and a rough footing count only. Framing lumber, railing, stairs and hardware are separate line items you'll want to price with your supplier or contractor.
Composite or wood decking — does it change the math?
The board-count math is the same either way; only the price per sq ft and board dimensions change. Enter your specific board's width and length for an accurate count.