Garden & outdoor
How many fence posts and panels do you need?
Posts, mesh or panels and concrete bags needed for your fence length and post spacing.
Quick answer
Fence math is simple but unforgiving: posts = length ÷ spacing + 1 (the +1 that everyone forgets is the closing post), plus two reinforced posts for every gate. Spacing depends on what hangs between the posts — rigid welded panels dictate exactly 2 m or 2.5 m, while rolled mesh tolerates 2.5-3 m, tighter in windy spots or on slopes.
Posts needed
15 posts
- Mesh / panel length
- 32 m
- Concrete (25 kg bags)
- 23 bags
Posts = length ÷ spacing + 1, plus 2 reinforced posts per gate. Each post needs a footing of roughly 30×30×50 cm — about 1.5 bags of 25 kg ready-mix concrete. Add corner and tension posts on long runs of mesh roll (one every 25 m and at every change of direction). Mesh length includes 5% extra for tensioning.
How it works
The part that decides whether your fence is still straight in ten years is underground. Each post wants a concrete footing about 30 × 30 cm wide and 50 cm deep — roughly 1.5 bags of 25 kg fast-set concrete per post, which is why the calculator’s concrete number is usually the surprise. On rolled mesh, add straining posts (braced diagonally) at every corner, every change of direction and every 25 m of straight run: mesh tension, not post count, is what keeps a wire fence from sagging.
Frequently asked questions
How many posts do I need for 30 meters of fence?+
With rolled mesh at 2.5 m spacing: 13 posts, plus 2 reinforced ones if there’s a gate — 15 total. With 2 m rigid panels: 16 posts. Add braced straining posts at corners and direction changes. For the footings, budget around 20-23 bags of 25 kg concrete.
How deep should fence posts go?+
The rule of thumb is a third of the above-ground height, with a 50 cm minimum: a 1.5 m fence wants posts in the ground 50 cm, a 2 m fence 60-70 cm. In frost-prone areas go below the frost line or the footing will heave. Set the post in fast-set concrete, check plumb with a level, and let it cure 24-48 hours before tensioning mesh.
Rigid panels or rolled mesh — which should I choose?+
Rigid welded panels cost 2-3× more per metre but look sharper, install faster (no tensioning) and survive impacts and climbing. Rolled mesh wins on budget, on long rural runs, and on uneven terrain where it follows the ground. A common compromise: panels on the street-facing side, mesh everywhere else.
Do I need planning permission for a fence?+
Rules vary by country and municipality, but common patterns: fences up to 1.8-2 m usually need no permit in rural or private settings, while street-facing fences often have height and material restrictions. Boundary fences shared with neighbours may require their agreement (and can split the cost). Check your local rules and the exact property line before digging — moving a fence 30 cm is expensive.
As an Amazon Associate I earn from qualifying purchases — the price does not change for you.