Decking Calculator – Woodworking Tools

Decking Calculator

Estimate decking materials for your outdoor project

Result will appear here

Frequently Asked Questions

How do I calculate decking boards?

Board count = (Deck width × 12) ÷ (Board width + Spacing). Add 10% for waste and cuts.

What spacing should I use between boards?

0.25″ is standard for pressure-treated lumber. Composite decking may require 0.125″ spacing.

Should I run boards perpendicular or parallel to the house?

Perpendicular is most common. Parallel may be used for diagonal patterns or specific aesthetics.

How much extra material should I buy?

10-15% extra is recommended for waste, especially for complex shapes or inexperienced installers.

What about joist spacing?

Standard joist spacing is 16″ on center. Check local building codes for specific requirements.