Fence Calculator

Fence calculator that counts posts, rails, boards or panels, concrete and gravel for wood, vinyl, aluminum or chain link, then prices that fence by length, layout, acres or budget.

How a Fence Calculator Counts Posts, Rails and Boards

A fence calculator splits the fence line into runs between corners, ends and gates, then counts sections, posts, rails and boards for each run. Counting per run matters because every gate opening adds a post on each side of it.

$$N_{posts}=\sum \left(\lceil \frac{L_{run}}{S}\rceil +1\right)-N_{corners}$$

L_run is the length of each run, S is the maximum post spacing and N_corners removes the posts that two runs share at a corner. Rails are the number of sections times the rails per section, and a 6 ft fence uses three rails, one per 24 in of height.

$$N_{boards}=\lceil \frac{12L_{net}}{w+g}\rceil$$

L_net is the fence length minus gate openings in feet, w is the board width in inches and g is the gap. A solid privacy fence has no gap, so 96 ft of net fence with 5-1/2 in boards takes 210 boards, or 231 with 10% waste.

For 100 ft of 6 ft wood privacy fence with one 4 ft gate, that adds up to 14 posts, 12 sections, 36 rails and 231 boards. At the starting prices, with stain on both faces, it costs $2,335 with 7% tax, or $23.35 per foot, and $2,091 left unstained.

Fence Post Spacing and Post Length

Wood fences and vinyl panels usually set posts 8 ft on center, which matches 8 ft rails and panels. The fence calculator starts aluminum at 6 ft and chain link at 10 ft, the spacing those systems are commonly built to.

A 100 ft wood fence with no gate needs 13 sections and 14 posts at 8 ft spacing. An 8 m fence, about 26.2 ft, needs 5 posts and 4 sections, with posts just over 2 m apart.

$$P=1.5\times H$$

P is the post length and H is the fence height. Quikrete's Fast-Setting Concrete Mix data sheet sets hole depth at half the post's above-ground height, which buries one-third of the post. A 6 ft fence needs 9 ft posts set 3 ft deep, so you buy 10 ft stock.

In cold climates, the fence calculator sets posts 6 in below the frost line you enter, so frost heave has less grip on them. With a 42 in frost line, a 6 ft fence post is buried 4 ft and the full 10 ft stock goes into use. The Fence Post Depth Calculator works through that depth on its own.

Concrete per Fence Post

Each hole is three times the post width, per the same Quikrete data sheet, so a 4×4 post (3-1/2 in) gets a 10-1/2 in hole. Concrete fills the ring around the post for the buried depth, with 6 in of gravel underneath for drainage.

$$V=\left(\frac{\pi }{4}{d}^2-A_{post}\right)\times \frac{D}{144}$$

V is concrete in cubic feet, d is the hole diameter in inches, A_post is the post cross-section in square inches and D is the burial depth in inches. A 4×4 post buried 3 ft takes 1.55 cu ft, which is 4.1 bags of 50 lb fast-setting mix at 0.375 cu ft per bag.

The common rule of two bags per post fits a shallow hole. Quikrete's own example uses two 50 lb bags for a 4 in post in a 10 in hole 2 ft deep, so a 6 ft fence set 3 ft deep needs about double that.

Across 14 posts on a 100 ft wood fence, that is 64 bags of 50 lb mix with 10% waste and 9 bags of gravel. Switching to 80 lb bags at 0.60 cu ft each cuts the bag count, though not the weight you carry.

How Much 100, 200, 500 and 1,000 Feet of Fence Costs

At the fence calculator's starting prices, 100 ft of 6 ft wood privacy fence costs about $2,335 to build yourself and $3,835 installed. Cost per foot drops as the run grows, because the gate and end posts are spread over more fence.

Every fence calculator row here has one 4 ft gate, 4×4 posts, 10% waste and one coat of stain on both faces. Starting prices include $13 per 8 ft treated post, $3.50 per 6 ft board, $6.50 per bag of concrete, $38 per gallon of stain and $15 per foot of installer labor, so enter your store's prices before you order.

The formula for fencing cost is the sum of each material quantity times its price, plus sales tax, plus labor per foot if you hire out the work. On the 100 ft wood privacy fence, posts and footings take 32% of the materials, boards 37%, rails and screws 17%, stain 10% and the gate the last 4%.

Wood vs Vinyl vs Chain Link Fence Cost

Chain link is the cheapest fence type to build, and vinyl privacy panels cost the most of these seven styles at the starting prices. Every row below is the same 100 ft, 6 ft line with one gate, except chain link and aluminum, which keep their own post spacing. Wood rows include one coat of stain on both faces, while vinyl, aluminum and chain link need none.

Vinyl costs more partly in the ground. Its 5×5 posts get 15 in holes, so each post takes 8.4 bags of concrete, and the 100 ft run uses 130 bags against 64 for wood. The Vinyl Fence Cost Calculator breaks that style down further.

A chain link fence calculator counts different parts. For 100 ft of 4 ft chain link, that is 4 terminal posts, 8 line posts, two 50 ft fabric rolls, 10 top rails, 4 tension bars, 12 tension bands and 80 ties, for $1,060 at the starting prices.

For a full wood privacy breakdown, the Wood Fence Calculator and Fence Picket Calculator go deeper into boards and pickets. Farm and pasture lines are covered by the Barbed Wire Fence Calculator.

Building a Fence on a Slope

A fence on a slope is built one of two ways. A racked fence tilts its rails to follow the ground with boards kept plumb, while a stepped fence keeps each section level and drops it at every post.

$$L_{slope}=L\times \sqrt{1+g^2}$$

L is the level length and g is the grade as a decimal, so a 10% slope is 0.10. Racked rails run 0.5% longer at that grade, which pushes an 8 ft section just past 8 ft and moves every rail onto 10 ft stock.

Stepping costs more in posts, and the fence calculator raises every post to match. At a 10% grade each 8 ft section drops 9-5/8 in, so every post stands that much taller, goes deeper and needs 12 ft stock. A triangle gap also opens under the downhill end of each section, which soil, gravel or a cut kickboard fills.

In the fence calculator, boards keep the same count either way, because they stay plumb and cover the level length. Pre-built panels usually step, since most can't rack, while chain link and aluminum follow the grade.

Fence Stain, Kickboards and Post Caps

The fence calculator figures about 6 gallons of stain for both faces of 100 ft of 6 ft fence at the 200 sq ft per gallon starting coverage, or 3 gallons for one face. Coverage varies widely by product and wood, so enter the rate from your can label.

A kickboard is a treated 2×6 along the bottom of each section that keeps the boards off the soil. On 100 ft of fence that is 12 kickboards and 48 more screws, about $108 at $9 per board, and it also closes the gap under a stepped section.

Post caps shed water off the cut end grain of wood posts. At $5 each, caps for 14 posts add $70, and vinyl and aluminum posts already include theirs in the system post price.

Linear Feet, Fencing Area and Fence by Acre

A linear foot of fence is one foot of fence line measured along the ground, whatever the height. Fencing area is length times height, so 100 ft of 6 ft fence has 600 sq ft of face, or 576 sq ft after a 4 ft gate.

A fence calculator uses square footage for stain and paint, while linear feet drive posts, rails and boards. The Deck Stain Calculator turns fence face area into gallons, and stain both sides by doubling it.

A fence calculator by acre treats the lot as a square. One acre is 43,560 sq ft, so each side is 208.7 ft and the perimeter is 834.8 ft, which takes 108 posts and about $18,678 of stained 6 ft wood privacy fence at the starting prices.

A 10 × 10 ft fence costs more per foot because corners and a gate sit in only 40 ft of line. The Rectangle Fence Perimeter Calculator finds the line length for any rectangular yard, and the Round Pen Calculator handles circular horse pens.

Fence Cost per Meter

A 20 m fence, about 65.6 ft, costs around $1,604 in materials for stained 6 ft wood privacy with one gate, or $80 per meter. The fence calculator works in meters for readers in Canada, the UK and Australia, though prices stay in dollars.

One meter of fence costs about $76.61 on a 100 ft run at the starting prices and climbs to $102 per meter on an 8 m run. Short fences pay for end posts and a gate over fewer meters, so the per-meter price is never a flat number.

Pool Fence Rules for a Barrier

A pool fence has to be at least 48 in tall, under the 2021 International Swimming Pool and Spa Code Section 305, as summarized by the City of Prosper, Texas. Gates must open away from the pool, close on their own and latch themselves.

Most picket fences fail the spacing rule. A 4 ft picket fence with two rails has them well under 45 in apart, so the pickets can't be more than 1-3/4 in apart, and the usual 3-1/2 in gap is too wide for a pool barrier.

Standard Fence Height and Permits

The standard backyard privacy fence is 6 ft tall, and front-yard fences usually run 3 to 4 ft. Many towns cap fence height by yard location in their zoning code, so check those limits before ordering longer posts.

The 2021 IRC Section R105.2 exempts fences up to 7 ft high from a building permit, as quoted by Grant County, Washington. Zoning approval and HOA rules can still apply to shorter fences.

Call 811 a few days before digging so buried utility lines get marked for free. A 100 ft fence means 14 holes up to 3-1/2 ft deep, and any one of them can hit a gas or power line.

Fence Calculator Waste and Store Tools

Store fence tools and estimating rules give different numbers, mostly because of waste allowances and the prices they assume.

What is a fence calculator?

A fence calculator turns a fence length, height and style into posts, rails, boards or panels, concrete and cost. A full one also handles gates, corners, post depth and the hole size that sets the concrete count.

How much fencing material should I buy?

Buy the counted quantity plus about 10% extra on boards and concrete for split boards, miscuts and spillage. Posts, rails and panels are counted exactly, and a spare post or rail is cheap insurance against one bad piece.

How does a Home Depot or Lowe's fence calculator compare?

Store fence calculators price their own stocked parts. Enter the same store's post, board, panel and concrete prices here to compare the full list, including concrete and gravel for every hole.