How many pickets for 100 feet of fence?

A length alone cannot determine the count

A 100-foot fence can use very different picket counts depending on picket width, Gap, Post width and Bay layout. Start by deciding whether the 100 feet describes an outside-to-outside Run, several Runs, or a boundary that also includes a Gate. Those are different inputs. The table on this page treats each length as one straight Run with 3.5-inch Posts and a maximum Bay clear length of eight feet. It excludes Gates, Corners, waste and the hardware needed to connect the assembly.

Use the table for an initial comparison, then open the 100-foot preset and replace its assumptions with your measured dimensions. The link uses 3.5-inch pickets and a 2.5-inch target Gap. It has one Run, so you will need to add any actual Gate or Corner in the correct order. The results update as you make those changes; there is no separate calculate step.

Why dividing 1,200 by six gives the wrong picture

One hundred feet equals 1,200 inches. If a picket is 3.5 inches wide and the desired opening is 2.5 inches, one repeated pitch is six inches. Dividing 1,200 by six gives 200. That is a useful rough magnitude, but it assumes all 1,200 inches belong to an uninterrupted pattern. In a real fence, Posts occupy some of the length, and each Bay has an opening at both ends. A repeated pitch alone does not account for either of those facts.

The planner first positions the Posts. With a 1,200-inch Overall Length, subtract the two end Posts and divide the provisional clear distance by the maximum Bay length. Round up to choose the number of Bays. Then deduct every Post, including the new intermediate ones, and divide the remaining length equally among those Bays. Only after the openings are established does the Member calculation run. The displayed count is therefore the sum of independently fitted whole counts, rather than a rounded quotient across the property boundary.

Read the generated table

The table below is generated at build time by the same Plan solver used by the interactive tool. It compares 50, 100, 150 and 200 feet; actual Member widths of 3.5 and 5.5 inches; and target Gaps of zero, one, two, 2.5 and three inches. “Installed pickets” is the sum across the Bays. “Posts” includes both terminal supports. The table’s Gap column states the target you requested, not a claim that every opening can achieve it exactly with whole stock widths.

A zero target deserves particular care. Equal mode may still leave a small residual Gap when the available opening is not an exact multiple of the picket width. This is not an overlap or privacy-panel calculator. If your fence uses overlapping boards, a shadowbox pattern or a manufacturer-specific panel system, choose the corresponding takeoff method. Do not treat the zero-target row as a guarantee that no sightline remains. Inspect the actual solved Gap in the interactive preset before ordering for a closed appearance.

Convert installed count to purchase count

After the geometry is settled, choose a waste allowance based on the stock you can actually buy and the cuts you expect to make. The default allowance is 10%. The planner multiplies the installed count by 1.10 and rounds up to a whole Member. For example, a layout with 120 installed pickets requires 132 at that allowance. Changing waste does not move a single mark; it only changes the purchase estimate. Keep the installed count separate when comparing layouts.

Extra material can cover damaged pieces, end trimming, rejected appearance and mistakes, but one percentage cannot predict every batch. Inspect the available stock before committing to the allowance. If decorative tops or orientation rules limit which offcuts can be reused, include that in your buying plan. Gate leaves are excluded from the Run picket count because the Gate is modeled as an opening. Add the leaf’s own material list separately rather than assuming that the fence count automatically includes it.

Nominal labels and actual widths

A nominal 1×4 and a measured 3.5-inch picket are not interchangeable inputs. The table uses actual widths. Measure the face that occupies horizontal space in the installed fence, then compare several pieces. Enter a metric width with its suffix if that is what your product documentation provides. A 90mm picket should be entered as 90mm, not as a bare 90, which the tool would interpret as inches. The unit cue beside every field remains visible to make that distinction explicit.

Width differences compound through an entire Bay. If your actual pickets are narrower than the value you used, the completed openings will be wider unless you regenerate the pattern. Do not correct that by repeatedly adding a small adjustment to a rounded pitch. Change Member width in the tool and use the new running positions. Each mark is calculated from the origin, so the final End Gap remains part of the same solved geometry rather than a leftover error.

Include openings and changes of direction

If your 100-foot boundary includes a Gate, measure the neighboring Runs from their respective outside Post faces. Enter the Gate leaf width and the required hinge and latch allowances separately. A 48-inch leaf with two 3/8-inch allowances needs a 48¾-inch clear opening in this model. Those are default arithmetic values, not hardware specifications. Use the values required by the actual hinge and latch system and verify that the installed opening matches them before assembling the leaf.

A right-angle Corner shares one Post between its neighboring Segments. The planner turns the following path clockwise around that center. Label the physical corner to match the Plan before reading the Post table. If your sketch turns left, rotate or reverse your representation carefully and verify the drawing, or split the job into supported Plans. This version does not infer arbitrary angles, closed-loop joins or site obstacles. The table’s simple straight-Run assumption is deliberately narrower than the full shape of many yards.

Make a purchasing worksheet you can verify

Record four items beside your estimate: the saved plan URL, the date of the measurements, the actual stock width and the allowance percentage. Print the Bay result table and the Rail cut list if you will discuss the order with a supplier. Rails are reported as cuts at the Bay Clear Length, not as an optimized stock purchase. Saw kerf, connection details and usable offcuts affect how many long Rails you buy. A total number of cuts is not the same as that purchasing optimization.

Before the full order, dry-check one representative Bay using the chosen Member width and its first and last running measurements. Inspect both End Gaps. If the real Post positions differ from the planned ones, update the affected dimensions and regenerate the takeoff. Use the formula reference to understand the difference between your rough division and the Bay-based result. The table gives a reproducible starting point, while the measured Plan gives the count you can relate to actual supports and openings.

Generated picket count table

One straight Run, 3.5-inch Posts, maximum 8-foot clear Bays, Equal mode. Installed counts exclude waste and Gates. Solved Gaps are display-rounded.