This page explains the measurement or planning assumption behind the result. When you need the project quantity itself, use Fence Picket Spacing Calculator.
Whole pickets force the gap to absorb the remainder
Pickets are discrete pieces. Once the opening and actual picket width are fixed, a whole-number count leaves a specific amount of open space. Equal spacing distributes that remainder instead of hiding it in one closing gap.
Equal edge gaps create count + 1 spaces
When a clear gap appears before the first picket and after the last, n pickets create n + 1 equal spaces. Subtract total picket width from the opening and divide the remainder by n + 1.
Flush edge pickets create count − 1 spaces
When the first and last pickets touch the two panel boundaries, only the interior openings remain. For n pickets there are n − 1 gaps, so the same leftover width is divided differently.
Maximum-gap mode is a constraint, not a promise to hit the target
The solver chooses enough whole pickets that the exact equalized gap does not exceed the entered maximum. The resulting gap is often smaller because there may be no whole count that lands exactly on the target.
Center pitch is useful for layout marks
For equal-width pickets, center-to-center pitch is picket width plus exact gap. Datum-based center or edge marks make it easier to check the full panel without accumulating rounding error.
Quantity comes after geometry
Once a panel layout is accepted, use the purchasing calculator to total pickets across panels and add reserve or bundle rounding. Do not inflate the layout count with waste before solving the visible gaps.
Regulated fence openings require separate verification
Pool barriers and similar applications are not cosmetic-only. The entered maximum gap must come from the rules/design that apply to the actual configuration, and spacing alone does not address gate, height, climbability or structural requirements.
Planning workflow
Measure the panel opening
Use the true clear layout field.
Enter actual picket width
Use the finished repeating face.
Choose outside-gap or flush-edge mode
This fixes the number of spaces.
Enter a project maximum or fixed count
Do not substitute a generic legal assumption.
Use the solved exact gap and datum marks
Check the closing edge before fastening.
Example: 96 in panel, 14 pickets
Fourteen 3.5 in pickets occupy 49 in. With equal outside gaps, 47 in of open space is divided among 15 spaces for a 3.1333 in exact gap. With flush edge pickets, that same 47 in would be divided among 13 interior gaps, producing a different layout.
Reference table
| Edge condition | Gap count | Exact-gap equation |
|---|---|---|
| Equal gaps at both edges | pickets + 1 | (opening − picket coverage) ÷ (count + 1) |
| First/last pickets flush | pickets − 1 | (opening − picket coverage) ÷ (count − 1) |
| Center pitch | — | picket width + exact gap |
Primary references for this planning guidance
These sources document the specific product or industry assumptions called out in this guide. Project specifications and the exact product instructions still take priority.
Supports: The installation guidance tells users to keep picket tops aligned with a guide and to use a spacer so decorative pickets maintain equal spacing rather than drifting across the run.
Boundary: The retailer guidance supports the field-layout workflow only. Product movement, fasteners, structure and permitted openings remain product/project/jurisdiction specific.
Supports: CPSC publishes configuration-specific opening, height, gate and climbability guidance for residential pool barriers and directs readers to local building/code authorities.
Boundary: This source is used to justify the calculator safety boundary, not to inject a universal fence-gap default. Local adoption, barrier configuration and complete project requirements must be verified separately.
Frequently asked questions
Why not just use a spacer block at the target gap?
If the target gap does not divide the panel exactly, repeated spacer placement leaves the closing gap different. Back-solving first gives one exact gap for the whole field.
Which edge condition looks better?
That is a design choice. The calculator supports equal outside gaps and flush edge pickets because they have different arithmetic; choose the condition that fits the project.
Does equal spacing reduce the number of pickets I should buy?
It determines the visible count in one panel. Purchasing still needs totals across all panels plus an explicit reserve for selection, damage and future repair.
Planning note: Product coverage, yield, package size, installation instructions and project requirements take priority over generic examples. Verify the exact product and project before purchasing.