Deck Materials – Full Lumber List

Instead of working from a supplier's ballpark figure, this calculator derives your deck materials requirement from Joists = W ÷ 0.4 + 1; Beams = Spans + 2; Posts = Beam Ends + Midspans; Rails = Perimeter ÷ post spacing using the exact deck dimensions and height you provide. The arithmetic stays transparent: each result links back to the displayed formula, so you can audit any number. For instance: A 6 × 4 m ground deck: 42 boards (14 × 400), 16 joists of 4 m, one doubled beam, 4 posts and 24 m of railing. Keep in mind: Add 10% to every line - lumber grades cull out the worst 5-8% per delivery. Quantities are rounded conservatively so offcuts, spillage and delivery shortages never stop work mid-job.

1. 1

   Take dimensions

   Note the deck dimensions and height for the area you are covering or filling.

2. 2

   Run the calculation

   The calculator applies Joists = W ÷ 0.4 + 1; Beams = Spans + 2; Posts = Beam Ends + Midspans; Rails = Perimeter ÷ post spacing the moment you type.

3. 3

   Check the breakdown

   Compare base quantity and waste-adjusted totals side by side.

4. 4

   Plan the purchase

   Use the final figure to price and schedule the delivery.

• Forgetting hardware and fasteners

• Unequal riser heights

• Building without permits