CalcMountain

Fence Calculator

Estimate all materials needed for a fence project. Calculates posts, rails, pickets, concrete for post holes, and nails/screws based on fence length and height.

Building a fence is a substantial materials calculation: posts, rails, pickets (or panels), concrete for post holes, fasteners, gate hardware, and stain or paint. Underestimating any one component means a return trip mid-project. This calculator handles the basic counts for a typical wood picket fence — posts at standard spacing (usually 8 ft on center), 2-3 horizontal rails per section, and enough pickets to cover the length.

A 100-foot, 6-foot-tall wood privacy fence typically needs about 13 posts (one every 8 ft + corners), 39 rails (3 per 8-ft section), 343 pickets (3.5" wide at 100 ft = 343 pickets), 13-26 bags of concrete (1-2 per post), and a few pounds of galvanized nails or screws. Materials cost ~$10-20/linear foot for cedar pickets, $5-12/linear foot for pressure-treated pine, $20-40/linear foot for composite. Add installation labor ($15-30/linear foot for typical residential pro install).

The biggest cost driver is the wood species. Pressure-treated pine is cheapest ($5-8/linear foot installed); cedar adds 30-50% but lasts longer and looks better aging; composite or vinyl doubles the cost but needs zero maintenance for 25+ years.

Inputs

Results

Posts Needed

14

Pickets Needed

364

Picket Cost

$1,092.00

Fence Materials List

ItemQuantityNote
Fence Posts148 ft long (4x4)
Fence Sections138 ft spacing
Rail Boards393 rails x 13 sections (2x4)
Pickets3643.5" wide x 6 ft tall
Concrete Bags (50 lb)282 bags per post
Screws/Nails45 lbsGalvanized or stainless
Picket Cost$1,092.00$3.00 each
Last updated:

Formula

**Number of posts:** Posts = (Length / Post spacing) + 1 (for corners and end posts) **Number of rails:** Rails per section = chosen by design (2 or 3 typically) Total rails = Sections × Rails per section Sections = Posts - 1 **Number of pickets:** Pickets = (Length × 12) / Picket width (In inches: 100 ft × 12 = 1200 inches / 3.5" picket = 343 pickets) For pickets with small gap: Pickets = (Length × 12) / (Picket width + gap) **Concrete for post holes:** 1 bag (50 lb) of quick-set concrete per typical 8-10" diameter × 24" deep hole. 2 bags per heavy-duty (gate, corner) post. Total bags ≈ Posts × 1.5 (average) **Worked example: 100 ft of 6-ft fence, 8 ft post spacing, 3 rails, 3.5" pickets** Posts: 100/8 + 1 = 13.5 → 14 posts Sections: 13 Rails: 13 × 3 = 39 rails Pickets: 100 × 12 / 3.5 = 342.86 → **344 pickets** (round up) Concrete: 14 × 1.5 = 21 bags Material cost: 14 × $15 (post) + 39 × $10 (rail) + 344 × $3 (picket) + 21 × $5 (concrete) = $210 + $390 + $1032 + $105 = **$1737** in lumber + concrete. Add fasteners, gate, stain: ~$2200 total materials. **Standard fence dimensions:** | Component | Typical size | |---|---| | Posts | 4×4 (for 6-ft fence) or 6×6 (for 8-ft fence) | | Top rail | 2×4 or 2×6 | | Middle rail | 2×4 | | Bottom rail | 2×4 | | Pickets | 1×4 or 1×6 (3.5" or 5.5" actual) | | Post height (in ground) | 2-3 feet (or below frost line) | **Post depth requirements:** - Below frost line in cold climates (36-48"). - Minimum 1/3 of total post length in ground. - For 6-ft fence: 8-ft posts with 2-3 ft in ground. - For 8-ft fence: 10-ft posts with 2.5-3 ft in ground. **Fence height by purpose:** - **3-4 feet**: yard boundary, decorative. - **4-5 feet**: pool fencing (code may require). - **5-6 feet**: pet containment (most dogs). - **6 feet**: privacy fencing (most common residential). - **7-8 feet**: tall privacy or noise abatement. **Cost estimates (2026):** | Material | $/linear foot installed | |---|---| | Pressure-treated pine | $5–12 | | Cedar (Western Red) | $10–20 | | Redwood | $15–30 | | Vinyl/PVC | $15–35 | | Composite | $20–40 | | Chain link (4 ft) | $4–8 | | Chain link (6 ft privacy slats) | $8–15 | | Aluminum (ornamental) | $20–40 | | Wrought iron | $25–60 | **DIY vs pro install:** - **DIY**: saves 40-60% on labor; takes 2-4 weekends for 100-ft fence. - **Pro install**: $15-40/linear foot labor on top of materials. - **Gates**: extra labor; typically $100-300 per gate installed.

How to use this calculator

  1. Enter total fence length in feet.
  2. Set fence height (4-8 ft typical).
  3. Choose post spacing (8 ft on-center is standard).
  4. Set picket width (3.5" for 1×4 pickets, 5.5" for 1×6).
  5. Choose number of horizontal rails (3 for 6-ft fence is standard).
  6. Enter price per picket; calculator returns counts and cost estimate.

Worked examples

Backyard privacy fence

**Scenario:** 200 ft of 6-ft tall pressure-treated pine privacy fence in backyard. **Calculation:** Posts: 26 (200/8 + 1, round up). Rails: 25 × 3 = 75. Pickets: 200 × 12/3.5 = 686. Concrete: 39 bags. At material costs ($12/post, $8/rail, $2.50/picket, $5/bag): $312 + $600 + $1715 + $195 = $2822 lumber + concrete. Plus fasteners ($75), one gate kit ($150), stain ($150): ~$3200 materials. **Result:** ~$3200 materials for DIY install. Pro install would add $3000-6000 in labor. Pressure-treated pine offers good value but requires staining/sealing every 2-3 years. Lifespan 15-20 years with maintenance.

Front yard cedar accent

**Scenario:** 50 ft of 4-ft cedar picket fence as front yard accent. **Calculation:** Posts: 50/8 + 1 = 8. Rails: 7 × 2 = 14. Pickets: 50 × 12/3.5 = 172. Concrete: 12 bags. At cedar pricing ($25/post, $15/rail, $4/picket): $200 + $210 + $688 + $60 = $1158. Plus fasteners, gate, finish: ~$1400 materials. **Result:** ~$1400 in cedar fence materials for accent fence. Cedar weathers to silver gray naturally; stain to maintain warm color. Lifespan 15-25 years without ground contact issues. Decorative gates add curb appeal.

Composite privacy fence

**Scenario:** 150 ft of 6-ft tall composite privacy fence with low-maintenance materials. **Calculation:** Composite is sold as panels (6×8 ft typical) plus posts. Need: 19 panels + 20 posts + post caps + brackets. At composite kit pricing (~$200/panel = $3800), plus $35/post × 20 = $700, plus mounting hardware ($300): ~$4800 materials. **Result:** ~$4800 materials for composite privacy fence. Twice the cost of pressure-treated pine, but zero maintenance for 25+ years. No staining, no warping, no rot. Long-term cost (purchase + maintenance over 25 years) often favors composite over wood for landlords and long-term homeowners.

When to use this calculator

**Use fence calculations for:**

- **Privacy fencing**: most common residential application. - **Pet containment**: choosing height and material for specific pets. - **Pool fencing**: meeting safety codes. - **Property boundary marking**: legal demarcation. - **Decorative gardens**: shorter ornamental fences. - **Security fencing**: tall fences with gates and locks.

**Material selection guide:**

| Need | Material | |---|---| | Lowest upfront cost | Pressure-treated pine | | Premium look + reasonable cost | Cedar | | Premium look + premium price | Redwood | | Zero maintenance | Vinyl or composite | | Security with visibility | Aluminum or wrought iron | | Maximum security | Chain link with razor wire (commercial) | | Pool barrier code compliance | Pool-rated fencing per local code |

**Permit considerations:**

- Most jurisdictions require permits for fences over 6 feet tall. - HOAs often have height, material, and style restrictions. - Setback requirements: typically 0-6 inches from property line. - Pool fencing: separate code requirements (self-closing/latching, no climbing aids). - Front yard fences: often restricted to 3-4 ft height.

**Installation tips:**

- **Post depth matters most**: shallow posts heave with frost. - **Set corners first**: stretch string to align middle posts. - **Concrete tip**: dry-pour concrete + water in hole vs. mixing in wheelbarrow saves time. - **Plumb every post**: 4-foot level on multiple sides. - **Crown rails up**: install with arch curving upward. - **Picket gaps**: 3/8" between pickets allows for wood expansion. - **Don't over-tighten screws/nails**: wood swells and contracts.

**Maintenance schedule:**

- Pressure-treated pine: stain/seal every 2-3 years. - Cedar/redwood: stain/seal every 3-5 years (or let weather naturally). - Vinyl/composite: power wash annually. - Metal: inspect for rust spots, touch up paint. - All: check posts annually, replace damaged pickets, tighten loose fasteners.

**Gate considerations:**

- Single gate: 3-4 ft wide for walk-through, 4-5 ft for wheelbarrows. - Double gate: 8-12 ft total for vehicle access. - Hardware: heavy-duty hinges, strong latch, optional lock. - Sagging prevention: anti-sag kit ($25) or diagonal cable. - Post for gate: 6×6 minimum (vs 4×4 standard) for strength.

**Common code requirements:**

- Pool fencing: minimum 48 inches tall, self-closing gate, no climbable horizontal members under 45 inches, vertical openings ≤ 4 inches. - Property line setback: vary by jurisdiction (0 to 6 ft). - Front yard height: 3-4 ft typical. - Backyard height: 6-8 ft typical max. - Specific neighborhoods: check HOA covenants.

Common mistakes to avoid

  • Setting posts too shallow. Frost heave displaces shallow posts; go below frost line in cold climates.
  • Spacing posts too far apart. 8 ft is standard maximum; closer for tall or windy areas.
  • Skipping post drainage. Add gravel base in post holes for drainage to prevent rot.
  • Using regular lumber instead of pressure-treated for ground contact. Untreated wood rots quickly.
  • Cheap fasteners. Galvanized or stainless steel is required for outdoor longevity.
  • Not allowing gap between fence and ground. 2-3 inch gap prevents direct soil contact and rot.
  • Skipping permit check. Some jurisdictions require permits for any fence; verify before building.

Frequently Asked Questions

Sources & further reading

SponsoredShop Top Deals on AmazonSupport CalcMountain — browse top-rated products at no extra cost to you.

Related Calculators