Fence Posts, Rails, Pickets and Concrete Calculator

Formula

N = ceil(Fence length/Maximum post spacing); P = N+1; V = π × ((Hole diameter/200)²-(Post diameter/200)²) × Hole depth/100 × P × (1+Waste allowance/100)

Planning estimate. Check product specifications and local requirements before purchasing.

Worked example: Complete Fence Project Calculator

Measurements in this example

Fence length30 m
Height1.8 m
Maximum post spacing2.5 m
Board face width10 cm
Rails per section2
Hole diameter30 cm
Hole depth80 cm
Post diameter10 cm
Waste allowance8 %

Calculated quantities

Fence sections12
Fence posts13
Horizontal rails26
Fence boards or pickets324
Concrete for post holes0.706 m³

What to check

This calculation uses: Fence length, Height, Maximum post spacing, Board face width, Rails per section, Hole diameter, Hole depth, Post diameter, Waste allowance. It returns: Fence sections, Fence posts, Horizontal rails, Fence boards or pickets, Concrete for post holes.

Measure each straight fence run and mark corners, ends and gates. Sloping ground may need shorter stepped sections.

The length is divided by maximum post spacing and rounded up to complete sections. One extra post closes the final section.

Posts and rails are planning quantities. Panels, pickets, fasteners, caps, braces and gate hardware depend on the chosen system.

Check exact post positions against boundaries, underground services and gate openings before drilling or digging.

Use the units beside each field. The values in the worked example are starting inputs; replace them with your measurements and the specifications of your material.

Compare alternatives

Open a tool, enter your measured dimensions, then save an estimate. Keep another version if you want to compare products or allowances.

Project sheet

Saved in this browser. Each entry keeps its own measurements. Quantities from different jobs are not added together.

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