Deck Material Estimator

16 inches on center is the most common spacing for residential decks and works well with standard 5/4 or 2× decking. Use 12-inch spacing for composite decking or longer spans, and 24-inch spacing only for thicker structural lumber.

Plan for 10-15% waste on deck projects to account for cuts, board defects, and mistakes. Complex designs with angles or patterns may need 20% waste, while simple rectangular decks can get by with 10%.

2×8 joists work for most decks up to 12 feet wide with 16-inch spacing. For wider spans or heavier loads, use 2×10 or 2×12 joists—always check your local building codes for span tables and requirements.

Use two screws at each joist crossing—for a 16-foot board with joists 16 inches apart, that's about 24 screws per board. A pound of deck screws contains roughly 100-150 screws depending on length.

All structural members (joists, beams, posts) and any wood touching the ground must be pressure-treated. Decking can be pressure-treated, cedar, composite, or other rot-resistant materials based on your budget and aesthetic preferences.