Fence calculator
Work out how many fence panels and posts you need.
Uses only the sizes you enter.
Show the workings
| Step | Sum | Answer |
|---|---|---|
| Panels | (18 m − 0.1 m post) ÷ (1.83 m panel + 0.1 m post), rounded up | 10 panels |
| Posts, one more than the panels | 10 + 1 | 11 posts |
| Length those make | 10 × 1.83 m + 11 × 0.1 m | 19.4 m |
What this leaves out or assumes
- A straight run with a post at each end. Add a post at every corner, gate or change of direction.
Where the figures come from
This sum uses only the numbers you entered.
How many fence panels and posts?
A straight run needs one more post than panels. Each panel and its post take up the panel's width plus the post's width, so divide the length by that and round up.
For an 18 m fence of 1.83 m panels with 100 mm posts: (18 − 0.1) ÷ (1.83 + 0.1) = 9.3, so 10 panels and 11 posts. Add a post at each corner, gate or change of direction.
Posts are usually set in concrete: the concrete calculator works out post holes.