Deck Calculator
Boards, joists and cost for a deck.
Enter your values
ⓘ Live results
Results
- Deck boards (16 ft)
- 28
- Board rows
- 26
- Joists at 16 in centres
- 13
- Deck area
- 192 sq ft
- Estimated board cost
- $504.00
Quick answer
Deck board count depends on deck area, board width and the gap between boards, plus joists at 16 inch centres.
How to use the Deck Calculator
- 1Enter your deck dimensions.
- 2Enter board width and spacing gap.
- 3Add 5% for cuts and defects.
Worked example
Using the values the calculator loads with:
Inputs
- Deck length16 ft
- Deck width12 ft
- Board width5.5 inches
- Gap between boards0.25 inches
- Price per board18 $
Results
- Deck boards (16 ft)28
- Board rows26
- Joists at 16 in centres13
- Deck area192 sq ft
- Estimated board cost$504.00
Frequently asked questions
What gap should I leave?
1/8 to 1/4 inch for pressure-treated boards that will shrink as they dry.
How deep are footings?
Below your local frost line — often 36–48 inches in cold climates.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.