๐งฑ Construction
Deck Calculator
Deck boards are laid across joists, so the board direction decides which dimension drives the count. Joists are then spaced 12 or 16 inches apart, and every footing needs a concrete pier below the frost line.
How it works
Deck length
Deck width
Deck board width
Joist spacing
Board direction
Waste allowance
Deck area
Deck boards (16 ft lengths)
Joists needed
Footings and posts
Concrete for footings
Frequently asked questions
How do I use the Deck Calculator?
Fill in the fields above โ the result recalculates instantly as you type. Everything runs in your browser, so the values you enter are never collected or stored.
Is this calculator free?
Yes. It is completely free, requires no account, and works on phones, tablets and desktops.