Fence Calculator

The calculator divides the fence length, after gate openings, by the post spacing and rounds up. Each corner starts a new spacing run, an open run adds a far-end post, and a closed loop reuses its starting post. Each gate adds two posts for the gate hardware.

An open run has two free ends, like a fence along one side of a yard. A closed loop wraps a full perimeter and meets itself, so the last span shares the starting post. The calculator uses one fewer post for a closed loop. For a 200 ft perimeter at 8 ft spacing, an open run needs 26 posts while a closed loop needs 25.

The calculator subtracts 4 ft per gate from the total fence length to get the picketed run, converts that to inches, and divides by the picket pitch (picket width plus gap), rounding up. For a 200 ft fence with no gates, 5.5 in pickets, and a 0.25 in gap: 2,400 in / 5.75 in = 418 pickets.

The calculator lets you estimate either two or three rails, but it does not design a fence. Fence height, wind exposure, soil, gates, material, span, and local rules determine rails, posts, footings, hardware, and attachment. Use the manufacturer's instructions and a qualified installer or engineer for a structural fence.

The calculator counts one 50 lb bag per post as a material allowance. It does not size the hole, footing, or concrete. Gate, corner, and end posts can need a different detail, especially in frost, wind, or expansive soil. Follow local requirements and a qualified installer or engineer for the actual design.