How many deck boards do I need?

Divide deck width by board width plus gap, then multiply by boards per row.

What spacing should I use?

Typical spacing is 1/8 inch for drainage and expansion.

Yes, add 5–10% for cuts and waste.

Estimate boards, spacing, and cost in seconds

Use this deck board calculator to estimate the number of boards, spacing, and total cost for your decking project.

Deck Length (feet) Deck Width (feet) Board Length (feet) Board Width (inches) Board Gap (inches) Cost per Board ($)

Enter your deck size, board dimensions, and cost to get instant results.

12×16 deck ≈ 30 boards and ~$750 total cost.

How many boards do I need?
Depends on deck size and spacing.

What gap should I use?
Typically 1/8 inch.