Calculating the Amount of Fencing for Horses

One major investment for a horse farm are installation and upkeep of fences. The fence should be safe and keep horses on the property. Fencing decisions should be based on the age of the animal, breed and temperament of the animal, production system, and situation. There are two types of fences - physical barriers, such as woven wire, high tensile, wood, and physiological barriers, such as poly wire, poly tape, low-tension smooth wire, and electric wire.
Horses are notorious for being harder on fences then other livestock. What happens when an excited horse hits a fence or horses are romping and accidently hit a fence? Because they are faster and stronger, they hit a fence with more force than other livestock. Horses also fight harder when caught in a fence compared to other livestock. Therefore, the fence must be very strong to withstand a horse hitting it, running into it, or being caught in it.
Horse fences should be 54 to 60 inches above the ground. A rule of thumb is to have the fence at least shoulder height of the horse you are fencing in. A good idea is to provide an 8-inch clearance on the bottom to allow animals such as rabbits to escape. The openings in fences should be either small enough where foals or small horses cannot get their hooves through or large enough where there is little chance of sticking a leg or head through. Small, safe openings are less than 3-inches square. Open spaces between rails or strands should be 12 inches or less. To discourage horses who reach over, scratch or lean on fences place a single strand of electric wire 4 to 6 inches above or just inside the top rail.
A large variety of fencing materials exist and all of them have advantages and disadvantages. Plan the fence and especially the foundation or posts. Recommended spacing between posts are as follows:

  • woven wire - 14 to 16 feet
  • high tensile wire - 16 to 90 feet
  • electric wire - 20 to 90 feet

When planning a fence, layout the property into number of paddocks/pastures, size of paddocks/pastures, types of fence posts needed and fencing used A line post is used when there will be fence passing straight through on each side. Corner posts are used when there is a 90-degree turn. End posts are used at the end of runs or for in-between gates. A plan with the types of fence posts for a pasture is illustrated.

Fence posts
Example of designing fencing for a pasture

Calculating the length of fencing for 1 acre

  • 1 Acre = 43,560 square feet
  • Area (acres) = (Length in feet) * (Width in feet)/43,560 sq. ft. /acre
  • For a square one-acre pasture - The square root of one acre is 208.47 square feet so one possibility is a square acre that is 208.5 feet long and 208.5 feet wid

Calculating the length of fence required for nearly square or rectangular pasture or paddock

  • Length (ft.) = 2[(Length in feet) + (Width in feet)]
  • Example = Length (500 feet) + Width (300 feet) * 2 =1600 feet total

Useful Web-Sites for Fences