Decking Calculator
Find how many deck boards you need for a new deck, based on its size and the boards you plan to use.
Your result
Deck boards needed
28 boards
Deck area
192 ft² · 17.8 m²
Rows of boards across the width
26
Counting deck boards
Each board covers its width plus the gap beside it, multiplied by its length. Divide the deck area by that coverage and add 10% for offcuts and boards rejected for defects.
A nominal 6-inch US deck board is actually 5.5 inches wide; common UK boards are 120–145 mm wide. Leave 3–6 mm (about ¼ in) between boards for drainage and timber movement.
Frequently asked questions
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