Fence Calculator (Posts + Pickets + Rails)
Plan a fence by total linear footage — get post count, rail lineal feet, picket count, and material cost in one shot, across wood, vinyl, chain-link, and composite options.
Fence Calculator
Enter project dimensions below — results update instantly. Switch units freely.
Estimates assume typical industry density and waste factors. Always verify with your supplier and local building code before purchasing material.
Post Spacing: The #1 Factor in Fence Lifespan
Too-far-apart posts cause every major fence failure. Rails sag between posts; pickets tilt as the rails flex; the entire run racks in high winds. Tight post spacing costs marginally more upfront but extends fence life by 10+ years.
Standard spacings:
- Chain-link: 10 ft (top rail takes the load)
- Wood privacy (6 ft tall): 6-8 ft — 8 ft is IRC max, 6 ft is prudent for high-wind regions
- Wood picket (3-4 ft tall): 6-8 ft
- Vinyl privacy: 6 ft only — vinyl rails sag more than wood
- Composite: per manufacturer, usually 6-8 ft
- Wrought iron / metal: 5-8 ft depending on pattern
If your fence will see strong wind loads (open fields, hilltops, coastal), drop to 6-ft spacing regardless of material. The extra posts cost $150-300 on a 100-ft run; storm damage costs $2,000-4,000 to rebuild.
Post, Rail, and Picket Count Formulas
Rails = Length × Courses
Pickets = (Length × 12) ÷ Picket Spacing (inches per picket)
For a 6-ft-tall wood privacy fence:
- Posts: 4×4 or 6×6 pressure-treated, 2 ft below grade + fence height above = 8 ft total
- Rails: 2×4 or 2×6, typically 3 courses (top, middle, bottom) for 6-ft privacy
- Pickets: 1×6 × 6 ft, spaced at 5-5/8 in center-to-center (no gap privacy) or 7 in (spaced picket)
Concrete per post:
- 8-in diameter × 2 ft deep = 0.7 ft³ = 2 bags of 60-lb premix
- 10-in diameter × 2.5 ft deep = 1.36 ft³ = 4 bags of 60-lb
| Fence Type | Material $/lf | Installed $/lf | Lifespan |
|---|---|---|---|
| Chain-link 4 ft | $7-10 | $14-25 | 15-20 yr |
| Wood picket 3 ft | $10-15 | $20-35 | 10-15 yr (wood) |
| Wood privacy 6 ft | $15-25 | $28-45 | 15-20 yr |
| Wood privacy 8 ft | $22-35 | $38-60 | 15-20 yr |
| Vinyl privacy 6 ft | $28-45 | $45-75 | 20-30 yr |
| Composite privacy 6 ft | $40-65 | $65-110 | 25-35 yr |
| Aluminum / metal ornamental 4 ft | $22-45 | $38-80 | 30-50 yr |
| Wrought iron 4 ft | $30-60 | $55-110 | 50+ yr |
Includes posts, rails, pickets/panels, gates, and typical hardware. Excludes labor for grading, stump removal, or difficult access.
| Fence Length | 6-ft spacing | 8-ft spacing | 10-ft spacing |
|---|---|---|---|
| 50 ft | 10 posts | 8 | 7 |
| 100 ft | 18 | 14 | 12 |
| 150 ft | 26 | 20 | 17 |
| 200 ft | 35 | 26 | 22 |
| 300 ft | 51 | 39 | 32 |
| 500 ft | 84 | 63 | 52 |
Count includes corner and end posts. Add 1 gate post per gate. Add 1 gate latch post per single gate, 2 per double gate.
Real-World Example Calculations
Backyard Privacy 150 ft × 6 ft Cedar
Standard backyard privacy fence with 1 single gate.
- Length
- 150 ft
- Height
- 6 ft
- Post spacing
- 8 ft
Takeaway: Typical 4×4 cedar posts, 2×4 rails, 1×6 cedar pickets. Add $1,800-2,200 labor if hired.
Front Yard Picket 60 ft × 3 ft White
Traditional white picket fence across front yard.
- Length
- 60 ft
- Height
- 3 ft
- Post spacing
- 6 ft
Takeaway: Pre-primed pine or vinyl picket panels simplify install. Allow time for 2 coats of paint if pine.
Large Property 400 ft Chain-Link 4 ft
Security fence around 1-acre property.
- Length
- 400 ft
- Height
- 4 ft
- Post spacing
- 10 ft
Takeaway: Chain-link is fastest and cheapest per linear foot for long runs. Upgrade to vinyl-coated fabric for aesthetics (+$2/lf).
Frequently Asked Questions
How much does a fence cost per foot?
Installed in 2026: Chain-link $14-25/lf, wood privacy $28-45/lf, vinyl $45-75/lf, composite $65-110/lf, ornamental iron $55-110/lf. Material-only runs 40-60% of installed cost.
How far apart should fence posts be?
6-8 feet for most residential fences. Chain-link can go to 10 ft. Vinyl max 6 ft. In windy areas, always use 6 ft spacing. Closer spacing = stronger, longer-lived fence.
How deep should fence posts go?
Minimum one-third of post length. A 6-ft fence uses 8-ft posts buried 2 ft deep. For tall fences (8 ft+) or high wind, go to 30-36 inches. In frost zones, always go below frost line (24-66 in depending on climate).
How much concrete per fence post?
Standard 8-in diameter × 2-ft hole: 2 bags of 60-lb concrete (0.7 ft³). Heavier 10-in × 3-ft hole for gate posts or tall fences: 4 bags. Use fast-setting mix for faster installation.
What's the cheapest fence to install?
Chain-link ($14-25/lf installed) for utility uses. Wood picket ($20-35/lf) for traditional front-yard looks. Wood privacy ($28-45/lf) for privacy at moderate cost. Cheapest per-lf isn't always cheapest per-year — vinyl costs more upfront but outlasts wood 1.5-2×.
How long does a wood fence last?
Cedar or redwood: 15-20+ years with periodic staining. Pressure-treated pine: 10-15 years (posts often fail first). Composite and vinyl: 25-35 years. Wrought iron: 50+ years with rust maintenance. Post life determines total fence life — rotted posts cause collapse even when pickets are fine.
Do I need a permit for a fence?
Varies by jurisdiction. Many areas require permits for fences over 6 ft in back yard or 4 ft in front yard. Also required for fences on property lines, in historic districts, or affecting sight lines at corners. Always check local zoning before starting.