🪥 Deck Board Estimator

Get exact board counts and calculate fasteners for any sized deck layout.

Total Boards Required

Deck Boards

Total Deck Area: 0 Sq. Ft

Deck Screws Needed: 0 Screws

* Assumes standard 5.5" wide decking boards with Â¼" spacing, and 16" on-center joists for screw counts. Includes 10% waste.

📏 Deck Surface Math

Deck boards are usually estimated in Linear Feet and then converted into actual piece counts based on the board lengths available at your lumber yard.

      Total Boards = CEIL(((SqFt / (5.75 / 12)) / Board Length) x 1.10)
    

The Gap Multiplier: We assume standard 5.5" wide decking (wood or composite) with a 1/4" gap for drainage and expansion. This makes each "course" of boards 5.75" wide.
Screw Counts: For 16" on-center (OC) joists, you should expect to use roughly 3.5 screws per square foot. This accounts for 2 screws at every joist intersection.
Lumber Matching: Whenever possible, buy the board length that matches your deck's longest dimension to minimize "butt joints" which are the first places a deck will rot or fail.

💡 Expert Tip

If your deck is 16 feet wide, buy 16-foot boards even if 8-foot boards are cheaper per foot. A deck with continuous boards looks much more professional and will have fewer water penetration points on the joists below.