How the fence calculation works
Net fence run = total length − gate openings. Panel count is rounded up from net run ÷ panel width. Post count is estimated from net run ÷ spacing, plus one and any extra corner/terminal posts.
Worked example
For a 30 m run with one 1 m gate, the net fence run is 29 m. With 2.4 m panels, the basic estimate is 13 panels. At 2.4 m post spacing, the basic post estimate is 15, before considering the exact layout.
Guide: using this calculator accurately
For the full explanation, worked examples, measurement tips and FAQs, read the Fence Guide →.
Measure a fence line
Measure the actual fence run rather than the property boundary if there are setbacks, gates or sections that will not be fenced. For multiple sides, calculate each run separately.
How gates affect materials
Gate openings reduce the length of fence panels needed, but gates usually introduce additional posts, hardware and structural requirements. Enter gate openings here to avoid counting that space as regular panels.
Panel width versus post spacing
Panel width and post spacing may be related but are not always identical. The product system may specify the exact post centres, panel dimensions and installation method.
Corners and terminal posts
Straight-run mathematics does not capture every corner, end or gate condition. Extra posts may be needed at corners, ends and gate openings.
Common fence-calculation mistakes
Do not treat this as a structural design. Wind loads, soil, footing depth, fence height, material type and local requirements can change the correct post and footing arrangement.
Frequently asked questions
Does this tell me the exact number of fence posts?
No. It is a basic planning estimate. Use the fence manufacturer's installation instructions for the final post layout.
Should gate posts be stronger?
Many gate systems require different posts or footings because the gate adds load. Follow the gate and fence product specifications.
Can I use this for timber or metal fencing?
The length and spacing arithmetic can help with either, but the correct spacing and component sizes are product-specific.