What the calculator does
It takes a fence run, a gate count, a post spacing and a set of unit prices, and returns a bill of materials with a cost total. Everything is computed on the server, so the page works with JavaScript disabled and the resulting address can be bookmarked or sent to a builder.
Where the numbers come from
Panel widths, post spacings, hole sizes and bag yields are typical trade values for each country, checked against supplier catalogues. Retail prices are deliberately conservative mid-range figures: they are a starting point, not a quote, and every one of them can be edited in the form.
What it deliberately does not do
It does not know your ground, your local wind loading or your boundary. It assumes a straight run on level ground with posts at the spacing you enter. Rocky ground, slopes, corners and retaining situations need a site visit and a builder’s judgement.