Fence Post Calculator
Post layout is the foundation of every fence estimate, so this page isolates it. Enter the fence length, the spacing you intend to use, and how many corners, ends and gates the run contains; the engine removes gate openings from the total, works out estimated positions along the remaining run, and reports line posts, corner posts, end posts and gate posts separately as well as in total. Because nothing else is calculated, the page is the quickest way to check a layout before committing to a fence system — you can see immediately what changing spacing from eight feet to six does to the count, or what a second gate adds. Notes flag anything unusual about the layout as you go. It is aimed at anyone setting out a fence: homeowners checking quantities, contractors sanity-checking a take-off, and anyone who needs gate posts counted correctly for once.
Calculator input
What this calculator calculates
- Fence length and gate opening length in feet
- Net run available for line-post spacing
- Estimated post positions along the net run
- Line, corner, end and gate posts reported separately
- Total post count for ordering
- Layout notes when the inputs produce an unusual result
Projects this calculator covers
- Straight boundary runsThe simple case: length divided by spacing, plus the end posts that bookend it.
- Runs with one or more gatesGate widths removed from the run and their posts added explicitly, never implied.
- Boundaries with cornersTurns in the fence line counted as their own posts rather than line positions.
- Spacing comparisonsTesting what tighter spacing does to the count before the fence system is chosen.
How the calculation works
Gate openings are removed from the total run, spacing determines estimated post positions, and gate posts are counted separately.
Formula: Net run = total length − gate openings. Estimated positions = ceil(net run ÷ spacing) + 1; gate posts = gates × 2.
Worked example
100 ft fence, 8 ft spacing, one 4 ft gate
Exact post placement should follow the actual fence layout.
Reading the results
- Estimated positions versus setting out. The count is derived from arithmetic on spacing, ends, corners and gates. Real setting out must also accommodate slopes, fixtures and the position of the corners themselves.
- Gate openings are subtracted. A gate is an opening, not a line of posts. The engine removes gate width from the run before spacing is applied, then adds the gate posts explicitly.
- One post can do two jobs. A gate can share a post with the end of the run. The counts are reported by category so you can see how the total assembles rather than guessing at overlaps.
- This is quantity, not structure. Hole depth, concrete volume and post size are structural decisions handled by the fence page and local requirements — not by a spacing calculation.
Assumptions
Central engine assumptions can be inspected in the methodology view. User-entered prices never get replaced with invented market prices.
Practical planning guidance
- Sketch the run with corners and gate positions before entering anything, so the inputs match the real boundary.
- Measure the actual fence line rather than the property line; the two are rarely identical.
- Test the spacing you intend to use against the fence system, because panel and rail lengths set a practical limit.
- Count gates explicitly with their widths — an opening without a width cannot be removed from the run.
- Treat the total as an ordering figure and adjust on site once the corners are pinned.
Common mistakes
- Double-counting gate posts by also spacing line posts through the opening.
- Entering a gate width without a matching gate count, or the reverse, leaving the layout inconsistent.
- Assuming ends are included automatically — the default is two, but a run meeting an existing fence may need one.
- Using the count as a structural layout instead of a material estimate.
- Ignoring corners entirely and discovering mid-job that a turning post is not a line post.
Important limitations
Frequently asked questions
How many fence posts do I need?
Divide the net run — total length minus gate openings — by the spacing, then add the end, corner and gate posts you declare. The calculator reports each category and the total.
What spacing should I use?
Match it to the fence system: panels and rails come in fixed lengths that usually settle the question. The default is a common planning value you can change freely.
How are gate posts counted?
Each gate contributes its own posts on top of the spaced positions, because a gate needs a post at both sides of the opening.
Do corner posts count as line posts?
No. Corners are reported separately since they are positioned by the turn in the boundary rather than by spacing along a straight run.
Does this include concrete for the holes?
Not on this page. Use the fence calculator for hole volume, concrete and the rest of the component take-off.
Is the count exact enough to order from?
It is a strong ordering estimate. Final positions still get adjusted on site for slope, fixtures and where the corners actually fall.
Planning guides
Related calculators
Your estimate will appear here
Enter your dimensions, then calculate. Results stay tied to the tested engine.