High-Tensile Electric Fence Calculator
Calculate high-tensile electric fence wire, posts and energizer needs from perimeter and strand count for livestock and wildlife control.
How This Calculation Works
Wire length equals the perimeter times the number of strands, divided by the roll length, which is often 4,000 feet for high-tensile wire. Post count equals the perimeter divided by the post spacing, rounded up. Energizer size depends on the total wire length and the livestock being controlled.
Field Calibration & Rate Reference Chart
| Area | Square feet | Acres | Square field side |
|---|---|---|---|
| 1,000 sq ft | 1,000 | 0.023 | 32 ft |
| 5,000 sq ft | 5,000 | 0.115 | 71 ft |
| 10,000 sq ft | 10,000 | 0.230 | 100 ft |
| 0.25 acre | 10,890 | 0.250 | 104 ft |
| 0.5 acre | 21,780 | 0.500 | 148 ft |
| 1 acre | 43,560 | 1.000 | 209 ft |
| 5 acres | 217,800 | 5.000 | 467 ft |
| 10 acres | 435,600 | 10.000 | 660 ft |
| 40 acres | 1,742,400 | 40.000 | 1,320 ft |
| 100 acres | 4,356,000 | 100.000 | 2,087 ft |
Common Questions
How much high-tensile wire do I need per mile?
Multiply the perimeter by the number of strands. A mile of three-strand fence needs about 15,840 feet of wire, or four 4,000-foot rolls. Add extra for ties and corners.
How big an energizer do I need?
Size the energizer to the total wire length and the livestock, with more joules for long runs and heavy-coated animals. A mile of fence often needs a 6 to 12 joule energizer. Check the manufacturer's distance rating.
How many ground rods does an electric fence need?
Use at least three ground rods 6 to 8 feet deep, spaced 10 feet apart, and more in dry or sandy soil. A poor ground is the most common cause of weak shock. Keep the ground rods in moist soil.
How far apart should high-tensile posts be?
Space posts 20 to 40 feet apart on straight runs, closer on curves and slopes. High-tensile wire tolerates wide spacing because it is tensioned. Brace every corner and end.