Fence Wood Calculator
Calculate privacy fence posts, 2x4 rails, pickets, and post hole concrete bags for wood privacy and perimeter fencing.
14 Posts (4x4) + 39 Horizontal Rails (2x4)
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What Is a Fence Wood Calculator?
A fence wood calculator computes the total lumber and concrete required to install a wooden privacy or paddock fence. It models 4x4 treated posts, 2x4 horizontal backer rails, dog-ear cedar/pine pickets, and post hole concrete bags.
How to Use This Calculator
- Enter total fence perimeter length in feet.
- Enter fence height in feet (standard privacy fence is 6 ft).
- Select post spacing (6 ft or 8 ft OC).
- Choose picket width: 1x6 (5.5" actual) or 1x4 (3.5" actual).
- Review the required post count, rail boards, pickets, and concrete bags.
Fence Materials Equations
\text{Posts} = \left\lceil \frac{L}{\text{Spacing}} \right\rceil + 1, \quad \text{Rails} = \left\lceil \frac{L}{\text{Spacing}} \right\rceil \times \text{Rails/Bay}, \quad \text{Pickets} = \left\lceil \frac{L}{\text{Picket Width}} \right\rceil \times 1.05For a 6-foot privacy fence, 3 horizontal rails are required per bay. Fast-Setting concrete is calculated at 1.5 bags per post hole.
Worked Example
Scenario: Building a 100-foot privacy fence, 6 feet high, with 8-foot post spacing and 1x6 pickets.
Posts: (100 ÷ 8) + 1 = 13 + 1 = 14 treated 4x4x8 posts.
Rails: 13 bays × 3 rails per bay = 39 eight-foot 2x4 rails.
Pickets (5.5" wide): 100 ft ÷ 0.4583 ft = 218 pickets (+ 5% waste = 230 pickets).
Concrete: 14 posts × 1.5 bags = 21 bags of 50-lb Fast-Setting concrete.
Tips & Key Notes
- Always call 811 before digging post holes to mark buried utility lines, gas pipes, and electrical conduit.
- Use 3 horizontal rails on 6-foot fences; 2 rails are only acceptable on fences 4 feet or shorter.
- Keep fence pickets 1 to 2 inches off the ground to prevent moisture wicking from grass that rots picket bottoms.
Frequently Asked Questions
How far apart should fence posts be?
Standard fence post spacing is 8 feet on-center. In high-wind areas or on slopes, spacing posts 6 feet apart provides superior structural stability.
How deep should fence posts be set in the ground?
A good rule of thumb is to bury one-third of the post length in the ground (minimum 24 to 36 inches for a 6-foot fence). In cold regions, posts must extend below the local frost line.
How many 1x6 pickets do I need per foot of fence?
A 1x6 picket has an actual width of 5.5 inches. You need approximately 2.2 pickets per linear foot of fence (or ~22 pickets per 10-foot section).
What is the best wood for a privacy fence?
Western Red Cedar is the premier choice due to its natural rot resistance and minimal warping. Pressure-treated pine is the most economical and long-lasting alternative.
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