The Formula Behind This Calculator
Sections = round up (fence length / 8 ft)
Posts = sections + 1 for a straight run
Pickets = fence length x 12 / (picket width 5.5 in + gap 0.5 in) x 1.10 waste
Rails = sections x 2 (3 rails for an 8 ft fence), concrete = posts x bags per post for the height
A fence is a repeating bay: post, section, post. That one structure explains every number on this page. Posts are spaced 8 feet apart because rails and panels come in 8 foot lengths and lumber longer than that sags and warps between posts. The run therefore takes one more post than it has sections, the classic fence post error in reverse. Pickets are a coverage calculation just like deck boards: each picket covers its own width plus one gap, and the 10 percent extra covers the warped and split boards in every bundle. Concrete scales with the post count and height, because a taller fence is a bigger sail and needs a heavier footing to stay plumb.
Worked Example: 100 Feet of 6 Foot Privacy Fence
A backyard run of 100 feet, built as a 6 foot picket privacy fence with posts 8 feet apart. No gate in this run, corners counted in other runs.
- Sections: 100 / 8 = 12.5, round up to 13 sections.
- Posts: 13 + 1 = 14 posts, bought as 8 foot 4x4s so about 2 feet can be buried.
- Pickets: 100 x 12 / 6 = 200 pickets, plus 10 percent = 220 pickets.
- Rails: 13 sections x 2 rails = 26 rails of 2x4 by 8 feet.
- Concrete: 14 posts x 2 bags = 28 bags of 80 lb mix.
- Budget: posts about $170 to $280, pickets $440 to $880, rails $210 to $310, concrete $170 to $225. Total roughly $1,000 to $1,700 in October 2026 national retail pricing, before gates and hardware.
Switch the style to panels in the tool and the pickets and rails collapse into 13 panels: fewer pieces, faster install, and a total that lands in a similar range. The comparison is worth doing with your own length, because on short runs the panel labor saving rarely beats the picket price advantage.
A Complete Guide to Estimating Fence Materials
Fences fail on paper before they fail in the yard. The classic errors are a post count taken from the section count, pickets ordered by the foot instead of by coverage, and concrete figured for a garden fence under a privacy fence that catches real wind. This guide covers the full material list for a wood fence, how slope and corners change it, and what the job costs when a pro builds it.
Corners, Gates and Runs: Counting the Real Layout
The formulas here cover one straight run. A real yard is several runs meeting at corners, and each corner post belongs to both runs visually but is bought once, so count posts per run and subtract the shared corners. Gates deserve their own plan: hang a gate on posts set for the purpose, ideally 6x6 for a wide gate, and add a post wherever the gate swings from rather than stretching a section. On sloped ground, a picket fence can step in small increments or rack if the construction allows it, while panels must step a full panel height difference at each post, which can leave gaps under the low side that matter if you have a small dog. Walk the line with a tape and a sketch, run by run, and total the runs rather than estimating the whole yard as one number.
Posts, Depth and Staying Plumb
The post is the fence. Pickets are decoration by comparison. Use ground contact rated pressure treated posts, set them on a few inches of gravel so the end grain is not sitting in water, and crown the concrete slightly at the top so rain sheds away from the wood. Depth follows the one third rule and your frost line, whichever is deeper. A 6 foot fence on 8 foot posts has about 2 feet in the ground, which suits mild and moderate climates; northern builders bury 3 feet or more. Set all the posts first, let the concrete cure overnight, then hang rails and pickets the next day: a fence built on green concrete wanders out of line as you work, and the error compounds down the run.
What a Wood Fence Costs in 2026
Materials as of October 2026, based on national retail pricing: a pressure treated 4x4 post runs $12 to $20, a 6 foot dog ear picket $2 to $4, an 8 foot privacy panel $55 to $95, a 2x4 rail $8 to $12, and an 80 lb bag of concrete mix $6 to $8. That puts DIY materials for a 6 foot privacy fence near $10 to $17 per linear foot. Installed prices from published contractor surveys run $25 to $50 per linear foot for the same fence, with gates at $200 to $500 each installed. For the 100 foot example, that is roughly $1,000 to $1,700 in materials against $2,500 to $5,000 hired out, which is why fences are one of the most common DIY projects in the country.
Before You Dig and Build
- Call 811 a few days ahead so buried utilities are marked. It is free and legally required in most places.
- Confirm the property line with a survey or plat if there is any doubt. A fence 6 inches over the line is a rebuild.
- Check local rules: many towns cap backyard fences at 6 feet and require the finished side to face the neighbors.
- Buy posts a grade up if the store allows picking through the stack. Straight posts make a straight fence.
- Plan picket gaps with a spacer block cut to width, not by eye, so the rhythm stays even across gates and corners.