✓Measure each straight fence run and identify corners and gates before counting posts.
✓Post count is based on the number of spaces plus the end posts.
✓Panel count must be rounded up to full sections even when the last panel is cut.
Spaces = fence run ÷ maximum post spacing, rounded upPosts on a simple straight run = spaces + 1Panels = fence run ÷ panel width, rounded up 1. Map the fence runs first
Measure each straight run from corner to corner or end point. Treat gates as planned openings rather than hiding them inside one total length.
A sketch is useful because corners, ends and gate openings can require posts that a simple straight-line formula does not capture.
2. Use maximum spacing as a limit
If posts must not exceed a chosen spacing, divide the run by that spacing and round the number of spaces up. The actual spacing will usually become slightly smaller so the posts fit evenly.
Structural requirements vary by fence type, height, wind exposure, post material and local conditions. The calculator estimates quantity; it does not determine safe post spacing.
3. Calculate panels or pickets separately
Prebuilt panels are counted from panel width. Individual picket fences require a different calculation based on picket width and gap.
The final section may be shorter than a full panel, but you still need to purchase a full section unless your supplier offers custom sizes.
4. Add gates and special posts explicitly
Gate posts, corner posts, terminal posts and changes in elevation can require different hardware or post sizes. Keep them visible in the project plan.
Material cost per linear foot is useful for budgeting, but a detailed purchase list should also account for posts, concrete, rails, panels or pickets and gates.
Example: 100 ft straight fence with 8 ft spacing
- Fence run
- 100 ft
- Maximum post spacing
- 8 ft
- Panel width
- 8 ft
100 ÷ 8 = 12.5, so use 13 spaces. A simple straight run therefore needs 14 posts. Panels also round up to 13 full 8-ft sections before gate or corner adjustments.
Run your own numbers in the Fence Calculator →What to avoid
- Forgetting that posts are one more than spaces on a simple straight run
- Rounding spaces down and exceeding the maximum spacing
- Ignoring gate and corner posts
- Using panel count for an individual-picket fence
Before you order
- Sketch fence runs
- Mark corners and gates
- Measure total runs
- Choose maximum spacing
- Count panels or pickets
- Add special posts and hardware