How this estimate works
The calculator applies: ceil(length x width x (1 + waste/100) / coverage). Keep measurements in one unit system and round up when suppliers sell whole units.
Limitations
Joists, picture frames, breaker boards, stairs, clips, and board lengths are separate quantities.
Source to check
Read the authoritative guidance for decking calculator
Frequently asked question
Does this count joists? No. Estimate the substructure separately using its spacing and span.