Count fence panels, posts and gates by straight runs
Fence orders depend on how the total boundary length is divided by gates and straight panel spans. A gate interrupts the panel run and creates additional supporting endpoints. This calculator subtracts the combined gate openings from the measured fence line, divides the remaining length into an equal number of straight sections and rounds panel spans within each section. The estimated post count includes run endpoints and gate boundaries, rather than assuming every gate simply replaces a single panel with no extra hardware.
Panel allowance is applied only to purchased fence panels, while gate counts, posts and separately ordered rails remain tied to the calculated layout. For manufactured fence panels that already include horizontal rails, enter zero separately purchased rails to avoid counting framing twice. Concrete is calculated from an entered planned consumption per posthole and the actual volume yielded by each bag. Posthole dimensions and structural design are site-specific rather than inferred from overall fence length.
Panel, post and concrete-purchase formulas
Straight-run sections = gate count + 1
Panels = sections × ceil((non-gate length ÷ sections) ÷ maximum panel span)
Posts = panels + gate count + 1
Concrete bags = ceil(posts × specified concrete volume per hole ÷ stated bag yield)
Worked example: a 100-foot fence with one gate
A 100-foot fence includes one 4-foot gate, leaving 96 feet of panels. When the remaining fence is divided equally into two straight sections, each run is 48 feet. With a maximum 8-foot panel span, each straight section needs six panels. The base count is 12 panels and 14 posts, including gate-adjacent endpoints.
At a 5% spare-panel allowance, the purchase quantity rounds up to 13 panels. If the installer specifies 1.5 cubic feet of concrete per posthole and the chosen bag yields 0.6 cubic feet, the simple total is 35 concrete bags. A design with a gate near the end, multiple corners or different soil requirements can produce a different post count and footing quantity.
Where a fence materials plan needs site measurements
The equal-section assumption is useful for a preliminary order, but gates rarely fall exactly in the middle of each fence line. Corners, uneven terrain, slopes, changes in fence height and property-boundary setbacks can create additional short spans or specialized posts. An actual fence layout drawing should identify start and end posts, gate posts, corner bracing and any sections that cannot use full-width manufactured panels.
Postholes may need different diameters or depths depending on wind exposure, frost depth, soil conditions and the fence system. Do not select footing dimensions from this quantity calculator. Underground utilities should be located before digging. The optional price fields calculate materials purchases only; installation, demolition, disposal and permit requirements remain separate.
Fence material questions
Why can a gate increase the number of posts?
A gate creates two load-bearing boundaries that may require reinforced or differently sized posts. When a panel run is split, the new endpoints are not always interchangeable with an ordinary interior fence post. The model adds a post-count allowance for each gate-separated run, but real gate positioning and structural requirements must be checked on site.
Should I order separate rails with prefabricated panels?
Usually not if the selected panels already include all their structural horizontal rails. Enter zero for separate rails in that case. For site-built fences, the chosen rail count per panel can be used as a first materials estimate, although irregular spans and additional bracing may change the final quantity.
Does the concrete bag estimate determine the safe posthole size?
No. You provide the planned volume of concrete per posthole and a manufacturer's yield per bag; the tool only converts that known quantity to complete bags. Footing design depends on local ground conditions, frost requirements, loading and the intended fence construction.