Practical tools for measured work
Fence post spacing calculator
Calculate equal fence bays, post counts, centre positions and clear gaps for an open run or closed loop.
Calculate the layout, check the diagram, then print the result for the shop or jobsite.
Post chainage from starting centre
| Post | Centre distance (mm) |
|---|---|
| 1 | 0 |
| 2 | 2000 |
| 3 | 4000 |
| 4 | 6000 |
| 5 | 8000 |
| 6 | 10000 |
How it works
Bay count = ceiling(run length ÷ maximum centre spacing). Equal centre spacing = run length ÷ bay count. An open 10 m run with maximum 2 m bays needs five bays and six posts. A closed loop shares its start/end post and therefore has one post per bay. Clear space subtracts post width from centre spacing.
Current-input example
The result above uses these exact values. This snapshot is included when the page is printed so the output can be checked against the original measurements.
- Fence centreline run
- 10000 mm
- Maximum post centre spacing
- 2000 mm
- Post width along the run
- 100 mm
- Run topology
- Open run with two end posts
Primary result: Posts: 6.
Before using the result
- Measure from the datum or reference edge described by this tool, and do not mix inside, outside and centerline dimensions.
- Keep inputs in the displayed units and preserve more precision than the final cutting or purchasing tolerance requires.
- When the result is close to a limit, verify it with a test piece, field measurement, manufacturer drawing or qualified project professional.
Limitations
Run length is measured between post centres, not outside faces. Closed-loop coordinates are chainage along the perimeter; the diagram unfolds that run. Corners and gates require separate runs and shared-post reconciliation. This tool does not size footings, embedment, wind resistance or post sections.
Frequently asked questions
What should I verify before using this result?
Recheck the physical measurements, confirm that every input uses the displayed unit, and compare the result with the applicable drawing, product specification, code requirement or test piece.
Why might the finished result differ?
Real work can include thickness, kerf, seams, tolerances, hardware allowances, installation clearances or site conditions that are outside the calculation. The limitations section identifies the main exclusions for this tool.
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