Fence Calculator: Posts, Panels, and Material Quantity for Any Fence
Calculate fence posts, panels, rails, and pickets for wood, vinyl, or chain-link fences. Enter your perimeter and spacing to get a complete material list.
Nothing derails a fencing project faster than showing up to the job site with too few posts or the wrong count of panels. The math is simple once you understand how posts and panels relate to each other — but you need to account for corners, gates, and your specific panel width.
The CalcHub Fence Calculator calculates posts, panels, rails, concrete for footings, and gate hardware for any fence configuration.
The Basic Post and Panel Math
For a section of fence with panels of width W and total fence length L:
Number of Panels = Total Length ÷ Panel Width (round up) Number of Posts = Number of Panels + 1For a 100-foot run with 8-foot panels:
- Panels: 100 ÷ 8 = 12.5 → 13 panels
- Posts: 13 + 1 = 14 posts
Gates add posts but you subtract the gate width from the available fence length first.
Posts Required: Key Spacing Rules
Standard post spacing varies by fence type:
| Fence Type | Typical Post Spacing | Notes |
|---|---|---|
| Wood privacy (6-ft panels) | 6 ft on center | Pre-built panel width |
| Wood privacy (8-ft panels) | 8 ft on center | More economical |
| Split rail | 8–10 ft | Rails span between posts |
| Vinyl privacy | 6 or 8 ft | Per manufacturer panel |
| Chain-link | 6–10 ft | Terminal posts at ends/corners |
| Farm/ranch wire | 10–12 ft | With bracing at corners |
| Picket fence | 6–8 ft | With individual pickets between |
Material Estimate: 150-ft Privacy Wood Fence (6-ft panels, 6-ft height)
| Item | Calculation | Quantity |
|---|---|---|
| Fence panels | 150 ÷ 6 = 25 | 25 panels |
| Line posts (4×4) | 25 + 1 ends − 4 corners = 22 | 22 posts |
| Corner posts (4×4) | 4 corners | 4 posts |
| Gate posts (4×4) | 2 per gate (1 gate) | 2 posts |
| Post depth (1/3 underground) | 6 ft post → 2 ft below grade | — |
| Concrete per post (80 lb bag) | ~1 bag per post | 28 bags |
| Gate hardware | 1 set | Per gate |
Post Depth and Concrete
Posts should be buried at least 1/3 of their total length, or below frost line — whichever is deeper. In cold climates, frost lines can be 3–4 feet deep. An inadequate post depth is the most common reason fences lean and fail.
| Fence Height | Minimum Post Length | Burial Depth |
|---|---|---|
| 4 ft | 6 ft | 2 ft |
| 5 ft | 7–8 ft | 2–2.5 ft |
| 6 ft | 8 ft | 2.5–3 ft |
| 8 ft | 10–12 ft | 3–4 ft |
Cost Comparison: Fence Types
| Fence Type | Installed Cost per LF | DIY Material Only |
|---|---|---|
| Wood privacy (cedar) | $20–$45 | $8–$18 |
| Vinyl privacy | $25–$55 | $15–$25 |
| Aluminum ornamental | $30–$65 | $20–$35 |
| Chain-link (6 ft) | $15–$35 | $7–$15 |
| Split rail (2-rail) | $12–$25 | $5–$12 |
| Farm fence (4-wire) | $3–$8 | $1–$3 |
How close to the property line can I build?
Most localities allow fences on or right at the property line. Some have setback requirements (e.g., 2 ft) from property lines or rights-of-way. Check with your municipality, and have a surveyor mark your corners if you're uncertain — building a fence on a neighbor's property is an expensive mistake.
Do I need a permit for a fence?
In many areas yes — especially for fences over 6 ft or within certain setbacks. Fees are usually small ($30–$100), and permits ensure you don't inadvertently violate HOA rules or local codes.
How do I handle uneven ground?
Two options: stepped panels (each panel is level, with a gap at the bottom where the ground drops) or racked panels (panels follow the slope). Most pre-built panels can't be racked — they'll need to be cut or built on-site. Stepped panels leave gaps at the bottom which can matter for pet containment.
Related Tools
- Concrete Calculator — post footing concrete volume
- Land Area Calculator — total perimeter from plot dimensions
- Lumber Calculator — board feet for custom wood fence