Fence Material Calculator

Posts include 2 extra posts per gate opening · 10% waste built into picket count · Concrete assumes 80 lb fast-set bags · Post depth = ⅓ of total post length buried

Material quantities are estimates. Always confirm with your lumber yard before purchasing. Local code may require specific post sizes or concrete requirements.

Understanding the Calculator Inputs

This calculator gives you a complete material list — posts, rails, pickets, and concrete bags — for building a fence from scratch. It covers the 6 most common residential fence styles and outputs everything you need to hand to a lumber yard or supplier. Here's what each input means and where people commonly go wrong.

Fence Length

Enter the total linear feet of fence you need to build — the perimeter of the fenced area minus any sides you're not fencing. Measure along the ground at the fence line, not on a map or plan drawing (sloped ground adds length). If you're fencing an irregular shape, walk the perimeter with a measuring tape or wheel. Do not subtract gate openings — the calculator accounts for those separately using the gate count input.

Fence Height

Select the finished height of the fence — the portion visible above ground. 6 ft is standard for residential privacy fences in most US jurisdictions. 4 ft is common for decorative, picket, and pool fences. 8 ft is used for security applications and is restricted by local zoning in many areas. The post you buy must be taller than the finished fence height — posts are buried ⅓ of their total length. For a 6 ft finished fence, buy 9 ft posts (6 ft above + 3 ft below grade). The calculator accounts for this automatically in the post specification output.

Fence Style

Fence style determines the full material list — different styles use different post sizes, rail counts, picket spacings, and board dimensions. The calculator applies the correct specifications for each style automatically. See the fence style breakdown section below for a detailed comparison of all 6 styles.

Post Spacing

6 ft on center is standard for wood privacy and picket fences — it balances material cost with structural stability. 8 ft spacing is used for vinyl panels (which typically come in 8 ft sections) and some chain link installations. 10 ft spacing is standard for split rail fences, which use log rails spanning between posts. Wider spacing means fewer posts and less concrete but longer rails that must span the distance without sagging.

Gates

Each gate requires 2 dedicated gate posts — one on each side of the opening. These are in addition to the line posts along the fence run. The calculator adds 2 posts per gate to the post count and subtracts the gate width from the picket/panel count (gates are pre-hung or built separately). A standard walk gate is 3–4 ft wide; a double drive gate is 10–12 ft wide. If you're installing a double drive gate, enter it as 1 gate — the calculator reserves 2 posts for any gate regardless of width.

Concrete Per Post

2 bags of 80 lb fast-set concrete per post is the standard for a 6 ft fence in normal soil. Use 1 bag for light decorative fences in firm, clay-heavy soil. Use 3 bags in sandy, loose, or rocky soil where the post hole diameter must be wider to achieve stability. Corner and gate posts should always get 3 bags regardless of soil — they carry more load than line posts.

3 Real-World Fence Examples

Complete material lists for three common fence projects — every item you need to put in your cart or hand to a supplier.

Example 1 — Wood Privacy Fence (150 ft × 6 ft, 6 ft post spacing)

The most common residential fence project — a 150 linear foot backyard privacy fence, PT posts, cedar pickets.

Real-world note: Cedar pickets are the biggest variable in this budget — $4–$5 each at big box stores, $6–$8 each at local lumber yards for better quality (fewer knots, more consistent width, tighter grain). For a fence you'll look at daily, the upgrade to quality cedar pickets is worth every dollar. PT posts are used even in an all-cedar fence — posts must be in the ground, and PT is the only code-compliant option for ground-contact structural wood. Use our fence cost calculator for the full installed cost including labor ($2,250–$4,500 for this fence professionally installed).

Example 2 — Split Rail Fence (200 ft × 4 ft, 3-rail, 10 ft post spacing)

A classic split rail fence for a rural property or large yard — 200 linear feet, 3-rail, PT posts with cedar rails.

Real-world note: Split rail fences use mortised (pre-drilled) posts with holes that the rails slot into — no screws or brackets required. This makes installation fast but means you must match rail diameter to post hole size when ordering. Most split rail kits from lumber yards are pre-matched. Buy rails and posts from the same supplier to ensure compatibility. Split rail fences are not privacy fences — add wire mesh or welded wire behind the rails if the goal is to contain animals or children.

Example 3 — Wood Picket Fence (80 ft × 4 ft, decorative, 6 ft post spacing)

A classic white picket fence for a front yard — 80 linear feet at 4 ft height, 1×4 pickets at 2.5" spacing, cedar or PT throughout.

Real-world note: A 4 ft picket fence at 80 linear feet is a manageable weekend DIY project for one person with basic tool experience. The most time-consuming part is setting posts — rent a post-hole digger ($60–$80/day) rather than digging by hand for anything over 10 posts. Get all posts set and concrete cured (24–48 hours minimum) before installing rails and pickets. If painting white, prime and paint the pickets before installation — painting in place after installation is slow and misses the backsides.

Post Spacing Guide

Post spacing directly drives post count, rail count, and total material cost. The right spacing depends on fence style, rail material, and wind exposure.

Corner and End Post Rules

The first and last post of every fence run, plus every corner post, must be treated as structural anchor posts. They should be one size up from line posts (4×6 instead of 4×4 for a 6 ft privacy fence) and get 3 bags of concrete rather than 2. Corner posts handle lateral tension from both directions of fence — they're the posts most likely to lean if undersized or under-concreted. The calculator uses 4×4 posts throughout as a baseline — budget 4×6 posts for every corner and end in your plan.

Concrete Per Post — How Much Do You Actually Need?

The most common DIY fence mistake is under-concreting posts. A post that leans ruins the entire fence line and is expensive to fix after panels and pickets are installed.

The Frost Line Rule

Post holes must go below the local frost line — the depth at which ground freezes in winter. Posts buried above the frost line heave upward as the ground freezes and thaws, eventually pushing posts out of alignment or out of the ground entirely. Frost line depth: Southern states 0–6", Mid-Atlantic 18–24", Midwest/Northeast 36–48", Northern states and Canada 48–60"+. Check your local building department for the required frost depth before digging any post holes.

Fence Style Material Breakdown

Each fence style has a distinct material list. Here's what every style requires per 100 linear feet at standard 6 ft height (or noted height) and 6 ft post spacing.

Picket counts include 10% waste. Posts per 100 LF = (100 ÷ post spacing) + 1 rounded up. Wood privacy uses actual 5.5" wide 1×6 pickets with ½" gap.

Which Style for Which Purpose?

• Wood Privacy — best for backyard privacy, noise reduction, and security. Most popular residential choice. Needs staining/sealing every 2–3 years.
• Wood Picket — decorative front yards, classic look, defines property line without blocking light. Traditional American aesthetic.
• Split Rail — large properties, rural lots, defining boundaries without enclosing. Low material cost, fast installation, no pickets needed.
• Chain Link — security, pet containment, sports areas. Lowest material cost per linear foot. Not a privacy fence without slat inserts.
• Vinyl Privacy — zero-maintenance alternative to wood privacy. Higher upfront cost but never needs painting, staining, or sealing. Panels arrive pre-assembled.

What the Calculator Doesn't Include

The calculator gives you the structural material list. These items are always required and always purchased separately:

Hardware and Fasteners

Every fence project needs: galvanized or stainless screws (1.5–2 lbs per 100 linear feet of privacy fence), joist-hanger nails if using bracket rail attachment, post-to-rail brackets (optional but recommended for wood privacy fences — $1–$2 each, 2 per post), and post caps to prevent water infiltration at the post top ($1–$3 each). Budget $50–$150 in hardware for a 100 ft wood privacy fence.

Gate Hardware

The gate itself is not included — the calculator reserves the post count and opening. A pre-built wood walk gate (36" wide) costs $60–$150 at lumber yards. A pre-built vinyl gate runs $150–$300. Gate hardware (hinges, latch, cane bolt for double gates) adds $30–$80. Budget the gate separately using our fence cost calculator for a complete installed estimate.

Permits and Utility Locates

Most municipalities require permits for fences over 4–6 feet or in front yards. Permit cost: $50–$200. More importantly: before digging any post holes, call 811 (the national "Call Before You Dig" number in the US) to have underground utilities marked. This is free and legally required in all 50 states. Hitting a gas line or electrical conduit while digging post holes is dangerous and expensive.

Post-Hole Digging Equipment

For anything over 10 posts, rent a one-person gas-powered post hole digger (also called an earth auger) — $60–$90/day at most equipment rental yards. For large jobs or rocky/clay-heavy soil, rent a two-person towable auger — $120–$180/day. Digging post holes by hand with a manual clamshell digger is feasible for under 10 posts in normal soil; beyond that, the rental cost is worth every dollar.

Common Fence Material Estimation Mistakes

Buying Posts the Same Height as the Fence

This is the single most common mistake — buying 6 ft posts for a 6 ft fence. Posts must extend below ground ⅓ of their total length, so a 6 ft fence requires 9 ft posts. If you buy 6 ft posts and bury 2 ft (the minimum for any stability), you only get 4 ft of finished height. Always buy posts at 1.5× the finished fence height.

Not Accounting for Gate Posts

Gate posts are structural members that carry hinge load and must be set more heavily than line posts — larger diameter, deeper holes, more concrete. They're not included in the "posts per linear foot" calculation and must be counted separately. Every gate needs 2 dedicated gate posts. A fence with 3 gates needs 6 gate posts in addition to all line posts.

Calculating Pickets on Nominal Width

A 1×6 picket is actually 5.5 inches wide. Calculating picket count on 6 inches nominal produces a count that's 9% too low — roughly 20 pickets short on a 150 ft fence before waste is even added. Always use actual dimensions: 1×4 = 3.5" actual, 1×6 = 5.5" actual. The calculator uses actual dimensions automatically.

Using Standard Nails or Screws in PT Lumber

Modern pressure treated lumber uses copper-based preservatives (ACQ, CA) that corrode standard bright zinc-coated fasteners within 2–3 years, causing staining and fastener failure. Use hot-dipped galvanized (HDG) or stainless steel fasteners for all PT lumber connections. This applies to screws, joist hangers, post bases, and all structural hardware in contact with PT wood. Using the wrong fasteners voids most PT lumber warranties.

Not Calling 811 Before Digging

Calling 811 before digging any post holes is legally required in all 50 states and takes 2–3 business days for utilities to mark your yard. Hitting a buried gas line, electrical conduit, or water main while digging post holes creates immediate hazard and expensive repairs. The law puts liability on the digger if they didn't call 811 first. This is not optional and costs nothing.

How We Calculate

Post Count Formula

Posts = CEILING(Length ÷ Post Spacing) + 1 + (Gates × 2)

We divide the fence length by the post spacing and apply a ceiling function (always round up — you need a post at both ends of every section). Then add 1 for the final end post, and 2 extra posts per gate opening. This produces the minimum post count required — real projects often need a few extra for corners not captured in a single linear measurement, so always buy 1–2 spare posts.

Rail Count Formula

Bays = Posts − 1 − Gates · Rails = Bays × Rails per Bay

Rail count is based on the number of bays (spaces between posts) times the number of rails per bay for the selected fence style. Gate openings don't use rails (they're part of the gate). Rails are calculated in 8 ft lengths — the calculator outputs the number of 8 ft boards to purchase and notes that some boards span two bays if the post spacing is under 4 ft.

Picket Count Formula

Pickets = CEILING((Length − Gate Width) ÷ (Actual Picket Width + Gap)) × 1.10

Picket count uses actual board width (not nominal), adds the gap between pickets, divides into the usable fence length (subtracting estimated gate width), and applies a 10% waste factor. For wood privacy fences (1×6 pickets), the default gap is ½ inch. For wood picket fences (1×4 pickets), the gap is 2.5 inches for the classic spaced-picket look.

Frequently Asked Questions