Quick Answer
For permanent high-tensile electric fence, space line posts 60–80 feet apart on flat terrain. Reduce to 30–40 feet on slopes, curves, or in high-pressure livestock areas. Temporary polywire fences use step-in posts every 20–30 feet. Corner and brace posts require no more than 8 feet between brace posts for structural integrity.
Why Spacing Matters
Post spacing controls wire sag, fence stability, and cost. Wider spacing saves money on posts and installation time but allows more wire sag between posts, which can reduce effective fence height and allow wire to touch vegetation. Closer spacing is more expensive but provides better wire control, especially on uneven terrain. The correct spacing balances cost against the specific challenges of your terrain and livestock type.
Spacing Guidelines by Terrain
| Terrain | Recommended Spacing | Reason |
|---|---|---|
| Flat, open pasture | 60–80 feet | Wire stays taut; minimal sag |
| Rolling hills | 40–60 feet | Grade changes cause sag |
| Steep slopes | 20–40 feet | Gravity pulls wire down slope |
| Curved fence lines | 30–40 feet | Wire tension pulls outward on curves |
| Dense vegetation areas | 30–50 feet | More posts hold wire above brush |
| High-pressure livestock areas | 20–30 feet | Animals pushing against fence |
Post Types and Appropriate Spacing
Fiberglass posts (5/8" diameter): Best at 40–60 feet spacing on flat ground. On hills, use at 30–40 feet. These flex under pressure, which actually helps prevent wire breaking on rough terrain.
Steel T-posts: Can handle 50–80 feet on flat terrain. More rigid than fiberglass, so wire tension is held better. T-posts are heavier and more expensive to install.
Step-in plastic posts: Use at 20–30 feet maximum for temporary polywire. These have minimal anchoring and will lean or pull out if spacing is too wide.
Corner and End Post Requirements
Corner and end posts bear the full tension of the wire and must be substantially stronger than line posts. Minimum: 4–6 inch diameter treated wood posts, set 3–4 feet deep, with a proper diagonal brace. The brace post should be set at 1/3 to 1/2 the height of the corner post distance from the corner. Never space brace posts more than 8 feet apart. Double-post H-brace systems work well for high-tensile wire under heavy tension.
Saving Money on Posts
The biggest savings in electric fence installation comes from wider post spacing (where terrain allows) and using fiberglass instead of steel posts. Going from 40-foot spacing to 60-foot spacing on 1 mile of fence saves roughly 44 posts — about $130–$260 in post cost alone. Use close spacing only where terrain or livestock pressure demands it.
Our Recommendation
Start with 60-foot spacing on flat to gently rolling terrain for permanent high-tensile fence. Reduce to 40 feet on moderate hills. Add "sighter posts" (lightweight posts just to hold wire position) between main posts where sag is visible after installation. This approach minimizes post count without sacrificing fence integrity.