How to Use This Calculator
Enter your total fence length in feet. Set post spacing to 8 feet, which is standard for 6-foot privacy fencing. Set rails per section to 3 for a 6-foot board on board fence. A middle rail prevents the tall boards from warping under wind load.
Enter your board width in inches. Standard 1x6 boards are 5.5 inches wide. For the gap field, enter a negative number to represent overlap. An overlap of 1 inch means the gap is -1. Use the presets to load common configurations and hit Calculate for your complete material list.
How to Calculate Board on Board Fence Materials
Board on board uses a negative gap value to represent overlap. The formula is: Boards = Fence Length (inches) / (Board Width - Overlap), rounded up.
Example: 100-foot fence with 5.5-inch boards and 1-inch overlap.
- 100 ft x 12 = 1,200 inches
- Effective spacing = 5.5 - 1 = 4.5 inches per board
- Boards = ceil(1,200 / 4.5) = ceil(266.7) = 267 boards
Compare to a solid privacy fence: 1,200 / 5.5 = 219 boards. The 1-inch overlap costs you 48 extra boards (22 percent more). Posts: ceil(100 / 8) + 1 = 14 posts. Rails: 100 x 3 = 300 linear feet. Concrete: 14 x 2 = 28 bags.
Board on Board Fence Tips
Pre-drill the nailing pattern before you start. Mark a consistent overlap on each board with a pencil line and nail through the mark into the rail. Consistent overlap keeps the shadow pattern even from end to end. A jig made from scrap wood to set the overlap width saves time on long runs.
Alternate sides evenly. The board on board pattern places one board on the front of the rails and the next board on the back. If you lose count, the visual pattern on the fence face will show it. Count as you go or mark posts at the changeover point.
Use ring-shank or spiral nails or 2.5-inch deck screws. Smooth nails back out over time as boards shrink and swell with moisture changes. Ring-shank nails grip the wood fibers and do not back out. Two fasteners per board per rail is the standard.
Kiln-dried cedar costs more but stays straighter. Green lumber boards warp as they dry in place. If you use green pressure-treated boards, expect some cupping and twisting in the first season.
What to Buy
Boards: 1x6 cedar fence boards in 6-foot lengths. Buy in bundles of 50 or 100 for better pricing. Standard board on board uses 1x6 (actual 5.5 inches) for both front and back faces.
Posts: 4x4 pressure-treated ground-contact posts in 10-foot lengths for a 6-foot fence. Set 4 feet in the ground, leaving 6 feet above grade. Cut to finished post height after the concrete sets.
Rails: 2x4 pressure-treated boards in 8-foot lengths. For a 3-rail fence at 8-foot post spacing, 24 boards covers 100 linear feet (3 rails x 8 sections).
Fasteners: 1.75-inch ring-shank galvanized nails or 2.5-inch coated deck screws. Stainless steel fasteners are worth the extra cost for cedar to prevent black iron staining on the wood face.