Decking Calculator
Calculate decking accurately for your build. Get material quantities, waste allowances, and project cost breakdowns. Get results you can export or share.
Formula
Boards = ceil(Width / Board Width) x ceil(Length / Board Length) x (1 + Waste%)
Divide the deck width by the effective board width (including gap) to get rows, and the deck length by board length to get boards per row. Multiply for total count, then add the waste percentage for cuts and defects.
Frequently Asked Questions
How much waste should I add for decking materials?
For a standard rectangular deck, add 10% waste factor to your board count. For decks with angles, curves, or complex shapes, increase the waste factor to 15-20%. Diagonal decking patterns require 15% extra material compared to perpendicular layouts. Picture-frame borders and herringbone patterns can push waste to 20-25%. Shorter board lengths generally produce less waste since offcuts can be reused. Always round up your board count and consider buying a few extra boards to have matching replacements on hand.
What are the best decking materials for longevity?
Pressure-treated pine is the most affordable option at $2-4 per linear foot with a 15-20 year lifespan, but requires annual sealing. Cedar and redwood cost $4-8 per linear foot and naturally resist rot for 15-25 years. Composite decking from brands like Trex or TimberTech costs $6-12 per linear foot but lasts 25-50 years with minimal maintenance. PVC decking at $8-15 per linear foot offers the best moisture resistance. Ipe hardwood is the premium option at $10-20 per linear foot, lasting 40-75 years with exceptional hardness and beauty.
How many screws do I need for decking?
Plan for approximately 2 to 2.5 screws per square foot of decking when using face-fastening methods. For a standard 5.5-inch wide board on 16-inch center joists, you need 2 screws at each joist crossing, which works out to about 350 screws per 100 square feet. Hidden fastening systems use clips at each joist intersection, typically requiring one clip per joist per board. Use stainless steel or coated deck screws rated for your material type to prevent corrosion and staining.
Is Decking Calculator free to use?
Yes, completely free with no sign-up required. All calculators on NovaCalculator are free to use without registration, subscription, or payment.
How accurate are the results from Decking Calculator?
All calculations use established mathematical formulas and are performed with high-precision arithmetic. Results are accurate to the precision shown. For critical decisions in finance, medicine, or engineering, always verify results with a qualified professional.
Is my data stored or sent to a server?
No. All calculations run entirely in your browser using JavaScript. No data you enter is ever transmitted to any server or stored anywhere. Your inputs remain completely private.