Deck board calculator
Not a structural or building-code check; confirm joist spacing and span with your local code or a pro.
Result
Deck board calculator
- Units (required)
- Feet and inches
Boards
—
Enter the deck size, board, gap, spacing, and stock length.
Ballpark estimate, check before you buy or quote.
Not a structural or building-code check; confirm joist spacing and span with your local code or a pro.
Estimate for planning only. This is not tax, legal, accounting or financial advice. Results depend on the figures you enter. Check all numbers, rates and rules with the official source or a qualified professional before relying on them.
How this works and common questions
About this tool
Not a structural or building-code check; confirm joist spacing and span with your local code or a pro. Boards across the width round up from the board width plus the gap. Rows along the length round up from the stock length. Joists are the length divided by the spacing you type, plus one, rounded up.
How it works
Boards across equal the width divided by the board width plus the gap, rounded up. Rows along the length equal the length divided by the stock length, rounded up. Joists equal the length divided by the spacing you type, plus one, rounded up.
Rules
Not a structural or building-code check; confirm joist spacing and span with your local code or a pro. The tool does not check span, posts, or footings. A gap of 0 is allowed. A board width of 0 is not.
Questions
Does this check the building code?
No. It is not a structural or building-code check. Confirm joist spacing and span with your local code or a pro.
Can the gap be zero?
Yes. A gap of 0 is allowed. The board width must be more than 0.
Why do the counts round up?
A partial board or joist still needs a whole piece. The page states that counts round up.
Do I need an account?
No. The tools work without one. You only need to sign in to save your work.
Is what I type saved?
No. Nothing is saved unless you sign in and choose Save. Otherwise it stays on the page.
Do you show ads or sell my information?
No. We show no ads and we do not sell your information.
Is this tax or legal advice?
No. Results are estimates for planning. Check rates and rules with the official source or a qualified professional.
Sign in to save this. Your entries stay on screen.
Estimate for planning only. This is not tax, legal, accounting or financial advice. Results depend on the figures you enter. Check all numbers, rates and rules with the official source or a qualified professional before relying on them.