How the farm fence calculator works
Pick the animal first. It fills in the height, wires and line post spacing from extension guidance and offers only the fence types that suit it. You can still change every number.
Then give the fence line: enter the acres and choose a square or a 2:1 rectangle, draw the pasture on the map, or type the total length. Gates are cut out of the line, and the fence is split into straight stretches between corners, ends and gate posts.
- T-posts fill each stretch at your spacing, plus 10% for bent and lost posts.
- Wood posts go at every corner, end and gate, and in the H-braces that hold the wire tension.
- Wire is the fenced length times the number of strands plus 10%, divided by the roll length: 1,320 ft for barbed wire and polywire, 330 ft for woven wire, 4,000 ft for high tensile.
- Clips are one per strand on every T-post, plus 10%.
T-posts = sum over every stretch of (stretch length ÷ spacing, rounded up, minus 1), plus 10%
A worked example: 10 acres of cattle fence
A square 10 acre pasture is 660 ft on a side, so the fence line is 2,640 ft. With one 14 ft farm gate, 2,626 ft gets wire. Four strands of barbed wire, 54 in high, with T-posts every 12 ft:
- 236 T-posts: 214 line posts plus 10%
- 26 wood posts: 4 corners, 2 gate posts and 20 brace posts, with 20 brace rails
- 9 rolls of barbed wire, 11,554 ft of wire in total
- 942 T-post clips
- Installed, about $3,433 to $16,356 including the gate. The Iowa State budget figure for the same length is about $3,046.
The three full sides and the two stretches beside the gate are all longer than 165 ft, so each gets a double H-brace at both ends. At 40 acres the sides are 1,320 ft, and those three sides each need a braced pull post in the middle.
How much fence per animal?
| Animal | Recommended fence | Height | Wires | Line posts | Source |
|---|---|---|---|---|---|
| Cattle | Barbed wire | 54 in | 4 | 12 ft | Kentucky, WSU |
| Horses | Woven wire (non-climb) | 60 in | mesh | 12 ft | UGA |
| Sheep | Woven wire | 48 in | mesh | 14 ft | WSU, Kentucky |
| Goats | Woven wire | 48 in | mesh | 14 ft | WSU, Kentucky |
| Hogs | Electric | 24 in | 3 | 40 ft | WSU, NRCS Iowa |
| Deer exclusion | Electric | 72 in | 8 | 30 ft | Montana State |
The University of Kentucky Beef Book gives 3 to 5 barbed strands for cattle with line posts 12 to 14 ft apart. For horses, UGA sets a perimeter of at least 60 in with posts 10 to 12 ft apart, and NRCS California suggests avoiding barbed wire and steel T-posts around horses. Oklahoma State calls a 7 or 8 wire electric fence about 48 in high ideal for sheep. WSU puts hogs behind 3 low wires between 6 and 24 in.
We have no preset for bulls. None of the extension sources we read gives a bull-specific height or wire count, so treat a bull pen as a job for a heavier fence than the cattle default and ask your county extension office.
How is a farm fence braced?
Wire fences hold their tension at the ends, so every straight stretch needs an anchor at both ends. The calculator follows the University of Kentucky rule:
- up to 165 ft (10 rods): a single H-brace, one brace post beside the corner post
- 165 to 660 ft: a double H-brace, two brace posts
- over 660 ft: a double H-brace plus a braced pull post every 660 ft
Kentucky also asks for corner and gate posts at least 8 in across and brace posts of 5 in or more. UGA adds braced line assemblies at the foot and top of hills, so add a pull post wherever the line dips.
What does it cost to fence an acre?
Cost per acre falls as the pasture grows, because a bigger square needs less fence for each acre inside it. For barbed wire with one 14 ft gate, using the installed ranges from HomeAdvisor and Fixr:
| Square pasture | Fence line | Installed, per acre |
|---|---|---|
| 1 acre | 835 ft | $1,176 to $5,525 |
| 5 acres | 1,867 ft | $493 to $2,343 |
| 10 acres | 2,640 ft | $343 to $1,636 |
| 20 acres | 3,734 ft | $240 to $1,146 |
| 40 acres | 5,280 ft | $168 to $805 |
HomeAdvisor's national figure for livestock fence is $630 to $5,900 per acre, $1,700 on average. Iowa State Extension's 2024 budget gives $1.16 per foot for 5-strand barbed wire, $1.41 for woven wire, $0.92 for high tensile and $1.22 for electrified high tensile, for a 1,320 ft fence with labor at $20 an hour.
How wide should farm gates be?
Penn State Extension asks for equipment gates of at least 12 ft and up to 16 ft, and horse or handler gates of at least 4 ft, 5 ft preferred. UGA uses 14 to 16 ft for pasture gates. Each gate you add removes its width from the wire and adds two gate posts and their braces.
Next steps
Counting only rolls and strands? The barbed wire calculator compares 3 to 6 strands. The electric fence calculator sizes the energizer and ground rods, how much fence for 10 acres gives the fence line for a set area, and the fence calculator covers yard fences.