Fence Calculator
Work out how many fence posts and sections you need, based on total fence length and desired post spacing.
How to use the fence calculator
- Enter the total length of the fence you're building, in meters.
- Enter the desired spacing between each post, in meters — check the recommended maximum spacing for your fence material.
- The calculator shows the number of posts and the number of sections (fence panels) you need.
How the post count is calculated
The calculator divides the fence length by the post spacing, rounds up to the nearest whole section, and adds one extra post on top of the sections (since each section needs a post at each end, shared with the neighboring section):
Number of posts = Number of sections + 1
Standard post spacing varies by fence type: wood fences often have 2–2.5 m between posts, while heavier materials like wrought iron or masonry may require tighter spacing for adequate strength.
The posts decide how long the fence lasts
The materials list is dominated by boards and rails, but it is the posts that determine service life. A fence almost always fails at ground level, where the post sits in the transition between damp soil and air — that is where both rot and frost movement attack. Posts in ground contact must therefore be treated for that specific purpose, not merely be ordinary exterior-grade treated timber.
Burial depth should relate to fence height and to ground frost at the site. A common rule of thumb is that around a third of the post's length sits below ground, and that the hole is filled with free-draining crushed stone at the bottom so water does not stand around the post end. Set a post in concrete without drainage beneath and you have effectively built a container that holds water.
Frequently asked questions
Why is the number of posts one more than the number of sections?
Because each section (panel) needs a post at each end, and neighboring sections share the post between them. For a straight fence with n sections, you therefore need n+1 posts — one extra at each outer edge.
What's a common post spacing for a wood fence?
2–2.5 meters is common for most wood fences, but always check the manufacturer's recommendation for your specific fence system, since spacing affects both stability and material use.
Do I need extra posts at corners?
Yes, corners and direction changes usually require a dedicated post right at the bend point, in addition to the evenly spaced posts along each straight run of fence. This needs to be added on top of this calculator's base calculation.