Fence Post Installation Guide

Post Depth Rule of Thumb

The post hole should be at least one-third of the total post height. For a 1.8m fence, use a 2.4m post with 600mm in the ground. For exposed or windswept locations, increase to 750mm–900mm.

Postcrete vs Mixed Concrete

Postcrete (fast-setting post mix) is ideal for up to 20 posts — just pour dry into the hole, add water, and it sets in 10–20 minutes. For larger projects, mixed concrete (1:3:6 or ST1 mix) is more economical.

First and Last Posts

You always need one more post than the number of spans. A 20m fence with 1.83m panels needs 11 posts for 10 spans, plus 1 extra at the end. This calculator accounts for this automatically.

Fence Post Calculator

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