Fence Material Calculator

Posts include 2 extra per gate opening · 10% waste built into picket count · Concrete assumes 80 lb fast-set bags · Post depth = ⅓ of total post length · Buy 9 ft posts for a 6 ft fence · Call 811 before digging

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

Understanding the Calculator Inputs

This calculator generates a complete material list — posts, rails, pickets, and concrete bags — for building a fence from scratch. It covers 6 common residential fence styles and outputs everything you need to hand to a lumber yard or supplier.

Fence Length

Enter the total linear feet of fence — the perimeter of the fenced area minus any sides you’re not fencing. Measure along the ground at the fence line (sloped ground adds length vs a flat plan measurement). Do not subtract gate openings — the calculator accounts for those separately using the gate count.

Fence Height & Post Length

Select the finished height above ground. The post you buy must be taller than the finished fence height — posts are buried ⅓ of their total length. For a 6 ft fence, buy 9 ft posts. For a 4 ft fence, buy 6 ft posts. For an 8 ft fence, buy 12 ft posts. The calculator shows the correct post length in the results automatically.

Post Spacing

6 ft on center is standard for wood privacy and picket fences. 8 ft for vinyl panels (which come in 8 ft sections). 10 ft for split rail (log rails span between posts). Wider spacing = fewer posts and less concrete but longer rails that must span the distance without sagging.

Gates

Each gate requires 2 dedicated gate posts in addition to line posts. The calculator adds 2 posts per gate and subtracts the gate width from picket/panel count. Gate posts must always get 3 bags of concrete (not 2) — they carry hinge load. Enter the concrete setting at 2 bags for line posts and add the extra bags manually for gate posts.

3 Real-World Fence Examples

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, 1 gate.

Real-world note: Cedar pickets are the biggest cost variable — $4–$5 each at big-box stores, $6–$8 at lumber yards for tighter grain and fewer knots. 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 per the AWC. 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 — 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. Buy rails and posts from the same supplier to ensure rail diameter matches post hole size. 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, 1 gate.

Real-world note: A 4 ft picket fence at 80 linear feet is a manageable weekend DIY project. Rent a post-hole digger ($60–$80/day) for anything over 10 posts. Get all posts set and concrete cured (24–48 hours) before installing rails and pickets. If painting white, prime and paint the pickets before installation — painting after 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

First and last post of every fence run, plus every corner, must be treated as structural anchor posts. Use one size up from line posts (4×6 instead of 4×4 for a 6 ft privacy fence) and 3 bags of concrete instead of 2. Corner posts handle lateral tension from both directions — they’re the posts most likely to lean if undersized or under-concreted. 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. 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 depth before digging.

Fence Style Material Breakdown

Each fence style has a distinct material list. Here’s what every style requires per 100 linear feet at standard height and 6 ft post spacing (split rail at 10 ft).

• Wood Privacy — best backyard privacy, noise reduction, security. Needs staining/sealing every 2–3 years.
• Wood Picket — decorative front yards, classic look, defines property line without blocking light.
• Split Rail — large properties, rural lots, boundary definition. Low cost, fast installation, no pickets needed.
• Chain Link — security, pet containment. Lowest material cost per linear foot.
• Vinyl Privacy — zero-maintenance alternative to wood. Higher upfront cost but never needs painting or sealing.

What the Calculator Doesn’t Include

Hardware and Fasteners

Every fence project needs: galvanized or stainless screws (1.5–2 lbs per 100 linear feet of privacy fence), post-to-rail brackets (optional but recommended — $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. Use hot-dipped galvanized (HDG) or stainless fasteners for all PT lumber connections — modern ACQ/CA pressure treatment corrodes standard bright zinc-coated screws within 2–3 years.

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. A pre-built vinyl gate runs $150–$300. Gate hardware (hinges, latch, cane bolt for double gates) adds $30–$80. Use 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 ($60–$90/day). For rocky or clay-heavy soil, rent a two-person towable auger ($120–$180/day). Hand digging with a 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. 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 on 6 inches nominal produces a count that’s 9% too low — roughly 20 pickets short on a 150 ft fence before waste is 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 is legally required in all 50 states before digging any post holes and takes 2–3 business days for utilities to mark your yard. 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: Posts = CEILING(Length ÷ Post Spacing) + 1 + (Gates × 2) — ceiling function ensures a post at both ends of every section; the final +1 adds the end post; each gate gets 2 dedicated posts.

Rail count: Bays = Posts − 1 − Gates · Rails = Bays × Rails per Bay. Gate openings don’t use rails. Rail count uses 8 ft boards; the calculator outputs the number of 8 ft boards to purchase.

Picket count: Pickets = CEILING((Length × 12) ÷ (Actual Picket Width + Gap)) × 1.10 — uses actual board width (not nominal), adds the picket gap (0.5" for privacy, 2.5" for spaced picket), and applies 10% waste. Actual widths: 1×4 = 3.5", 1×6 = 5.5".

Post length guidance: Based on AWC (American Wood Council) prescriptive post embedment requirements: ⅓ of total post length buried minimum, with frost line depth always the governing factor in freeze-thaw climates.

Frequently Asked Questions