Calculate posts, rails, pickets and concrete needed for building a fence.
This fence calculator works out how many posts, panels or pickets, rails and bags of postcrete/concrete you need for a run of fencing. Enter the length, height and post spacing and it does the rest – for panel fences or picket (paling) fences, in metric or imperial.
| Fence type | Post spacing |
|---|---|
| Panel fence | 6 ft / 1.8 m (panel width) |
| Picket / rail fence | 6–8 ft / 1.8–2.4 m |
A 30 m run with 1.8 m panels needs about 30 ÷ 1.8 = 17 panels and 18 posts. Each post hole typically takes 1–2 bags of postcrete (or two 60 lb bags of concrete).
6 to 8 feet (1.8 to 2.4 m) is standard. Shorter spacing is stronger, especially for tall fences.
A general rule is 1/3 of the total post length underground. For a 6 ft fence, use 9 ft posts with 3 ft buried.
Typically 1-3 bags of 60 lb concrete per post depending on hole size. 2 bags is a safe average.
Concrete posts last longest and resist rot, while timber posts look more natural but should be pressure-treated and ideally set on a gravel base so water can drain away.
Set posts on a layer of gravel so water drains away, slope the concrete collar so rain runs off the timber, and always use pressure-treated posts rather than burying untreated wood.
