Fence Calculator
Calculate how many fence posts, rails, and boards you need for any fencing project based on perimeter and fence design.
ft
ft
ft
in
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Posts Needed
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Rails Needed —
Boards Needed —
How to Use This Calculator
- Enter the total fence perimeter in feet.
- Enter the post spacing and fence height.
- Enter board width and gap in inches and the number of rails per bay.
Formula
Posts = floor(Perimeter ÷ Spacing) + 1
Boards per bay = ceil(Spacing × 12 ÷ (board width + gap))
Total boards = Boards/bay × (Posts − 1) × (1 + waste%)
Example
Example: 120 ft perimeter, 8 ft spacing, 6 in boards, 0.25 in gap → 16 posts, 3 rails: 48 rails, ~216 boards.
Frequently Asked Questions
- Divide the total fence length by post spacing and add 1. For example, 100 ft ÷ 8 ft spacing + 1 = 14 posts.
- Standard post spacing is 6–8 feet for wood fences and 10 feet for chain-link. Closer spacing adds strength.
- For a standard 8 ft panel with 6-inch boards and 1/4-inch gaps, you need about 15 boards per panel.
- Rails run horizontally between posts. A 6 ft tall privacy fence typically uses 3 rails per bay; a shorter fence uses 2.
- Yes — add 5–10% to account for cuts, splits, and defects. The calculator includes a waste option.