Fence Calculator Guide: Posts, Panels, Spacing and Gates
Estimate fence panels and posts while accounting for gate openings, panel width, post spacing and extra corner or terminal posts.
A fence material estimate should separate the total fence run from gate openings, panel width and post spacing. Product systems differ, so the calculator is best used to create a preliminary shopping list before checking the chosen manufacturer’s installation system.
Measure the total fence run
Measure the planned fence line. For long or irregular boundaries, measure each section and add them.
Subtract gates
Enter the number of gates and their combined width. The calculator subtracts these openings before estimating panels and posts.
Estimate panels and posts separately
Panels are based on nominal panel width. Posts are estimated from net run and spacing, with extra posts available for corners, ends or gates.
Verify the chosen system
Panel width, post spacing, footing depth, hardware and gate requirements vary. Confirm the final bill of materials against the product installation instructions.
Formula
Net fence run = total length − gate openings. Panels = net run ÷ panel width, rounded up.
Worked example
For a 24 m run with one 1.2 m gate, the net run is 22.8 m. With 2.4 m panels, 10 panels are required after rounding up. Post count depends on the chosen spacing and additional terminal or corner posts.
Common mistakes to avoid
- Assuming every fence system uses the same panel width or spacing.
- Forgetting gate openings.
- Forgetting corner, end and gate posts.
- Treating a material estimate as a structural fence design.
Frequently asked questions
How many fence posts do I need?
Estimate the net run after gates, divide by the chosen spacing and add required corner, end and gate posts.
Does this calculator design a fence?
No. It is a material-planning estimate; structural and footing requirements need separate consideration.
Do gates affect panel count?
Yes. Gate openings are subtracted from the fence run before panels are estimated.
Use the Fence Calculator
Enter your project measurements in the calculator, review the result and compare it with the product or supplier information for your specific project.