How this calculator works
It works out how much deck surface each board covers (its width plus a small gap), divides your deck area by that, adds 10% for waste, and converts the total linear footage into whole boards.
Worked example — a 16 ft × 12 ft deck, 5.5 in boards, 16 ft lengths:
192 sq ft of decking → about 422 linear feet with waste → 27 boards.
192 sq ft of decking → about 422 linear feet with waste → 27 boards.
Board gap matters
A 1/8-inch gap between boards lets the deck drain and the wood breathe. The calculator includes that gap so you don’t come up short.
Frequently asked questions
What is a standard deck board width?
Most decking boards are 5.5 inches wide (a nominal 6-inch board).
How much extra decking should I buy?
Add about 10% for cuts, waste, and the occasional bad board.