Free Fence Calculator — Posts, Rails & Material List (2026)

How to Use This Calculator

1. 1Measure the total fence length in feet around your property line. Include all straight runs but measure gate openings separately.
2. 2Enter the fence height — standard residential heights are 4 feet (front yard) and 6 feet (backyard privacy).
3. 3Set the post spacing — 8 feet is standard for most wood fences, 6 feet for windy areas or tall fences.
4. 4Click Calculate to get a complete material list including posts, rails, and pickets.

About This Material

A wood fence consists of three main components: posts, rails, and pickets (or boards). Understanding each component helps you choose the right materials and build a fence that lasts. Posts are the vertical structural members set in the ground. Standard fence posts are 4x4 pressure-treated lumber (3.5 x 3.5 inches actual). For a 6-foot fence, use 8-foot posts — this allows 2 feet of burial depth plus the 6-foot fence height. For corner posts, gate posts, and end posts, upgrade to 6x6 lumber for extra strength. Pressure-treated posts rated for ground contact (UC4A or higher) are essential — untreated wood rots within 2 to 5 years when buried. Cedar and redwood posts offer natural rot resistance but cost 2 to 3 times more than treated pine. Post prices range from $8 to $15 each for 4x4x8 treated pine, $20 to $35 for cedar, and $15 to $25 for 6x6 treated posts. Rails are the horizontal members that connect posts and support pickets. Standard rails are 2x4 pressure-treated lumber cut to the post spacing length (typically 8 feet). Most fences use 2 rails (top and bottom) for heights up to 5 feet, and 3 rails (top, middle, bottom) for 6-foot and taller fences. The top rail sits 6 to 8 inches below the top of the pickets, and the bottom rail sits 6 to 8 inches above the ground. Rails cost $4 to $8 each for 8-foot treated 2x4 lumber. Pickets are the vertical face boards that provide privacy and define the fence appearance. The most common picket is a 1x6 dog-ear board (0.75 x 5.5 inches actual), though 1x4 boards (0.75 x 3.5 inches actual) are used for traditional picket fences. Dog-ear, flat-top, and French Gothic are popular picket profiles. Standard picket spacing is 0 inches for privacy fences (boards touching) to 2 to 3 inches for decorative picket fences. A 6-foot dog-ear picket costs $2 to $5 each in treated pine, $4 to $8 in cedar. For board-on-board or shadowbox styles, increase picket count by 50% since boards overlap. Fasteners matter more than most people realize. Use hot-dipped galvanized or stainless steel nails and screws — standard zinc-plated fasteners corrode within 1 to 2 years when in contact with pressure-treated wood. Each picket requires 6 to 8 screws (2 per rail connection). Budget $30 to $50 per 100 linear feet of fence for screws alone.

Installation Tips

• •Call 811 to mark underground utilities at least 3 business days before digging any post holes.
• •Set corner and end posts first, then run a string line between them to align intermediate posts perfectly.
• •Dig post holes 3 times the post width (10 to 12 inches for 4x4 posts) and one-third the total post length deep.
• •Add 4 to 6 inches of gravel at the bottom of each post hole for drainage before setting the post in concrete.
• •Plumb each post with a level on two adjacent sides before the concrete sets.

Common Mistakes to Avoid

• ⚠Not checking property lines — building a fence even 6 inches over the property line can result in a costly forced removal.
• ⚠Setting posts too shallow — posts buried less than 24 inches will lean or heave in freeze-thaw climates.
• ⚠Skipping the concrete — posts set in dirt alone will loosen and lean. Use at least 2 bags of 50 lb concrete per post.
• ⚠Attaching pickets before concrete fully cures — the weight can push wet-set posts out of plumb. Wait 24 to 48 hours.
• ⚠Not accounting for grade changes — on sloped ground, either step the fence panels or rack them to follow the slope.

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