How to estimate fence posts, rails, and pickets

Lay out posts before counting infill

Measure the intended fence line and divide it into sections that do not exceed the selected maximum spacing. Rounding up sections makes the actual spacing slightly smaller, which is preferable to creating an oversized final bay.

Corners, ends, gates, and changes in direction should be marked individually because they may need distinct posts and hardware.

Convert sections into rails

Multiply sections by the planned number of rails per section. Rail count assumes stock pieces span each bay. If available stock is shorter, if rails overlap posts, or if a proprietary panel system is used, follow that system’s module and coverage instead.

Use actual picket width and gap

Convert the run to inches and divide by actual picket width plus the installed gap. Round up, then add a cut-and-selection allowance. Subtract gate openings before calculating field pickets and estimate gate frames and hardware separately.

• Check whether the final layout leaves a narrow cut picket.
• Account for stepped or racked sections on slopes.
• Keep replacement pickets from the same product line when practical.

Verify the site before digging

Confirm property information, easements, utility locations, permits, height and setback limits, soil and frost conditions, wind exposure, post embedment, treatment, fasteners, and corrosion resistance. The material count is not permission to build or a structural design.