A board width is not a panel-system input
The wood branch repeats a board-width-plus-gap interval across the net run. Post spacing separately determines straight-run sections. The form does not ask for panel dimensions, the relationship between panel width and post positions, or a component catalogue. Selecting a wood label does not activate those missing inputs.
This distinction matters even when both calculations return whole items. The noun attached to the result tells you which model was used: Pickets / slats remains a wood-infill count. It does not become a panel count because the number happens to look suitable.
Compare the arithmetic, not two product specifications
The examples below use hypothetical 5.5 in boards, zero gap, no gates, 6 ft height and 8 ft post spacing. Board counts were obtained by executing this site's submit handler. The last column independently divides length into hypothetical 8 ft intervals and rounds upward. Those intervals are not actual panels, a recommended size or a supplier specification.
| Total length | Actual wood-infill calculation | Pickets / slats | Independent interval arithmetic |
|---|---|---|---|
| 16 ft | ceil(16 × 12 ÷ 5.5) | 35 | ceil(16 ÷ 8) = 2 |
| 20 ft | ceil(20 × 12 ÷ 5.5) | 44 | ceil(20 ÷ 8) = 3 |
| 100 ft | ceil(100 × 12 ÷ 5.5) | 219 | ceil(100 ÷ 8) = 13 |
The comparison shows why you cannot take 219 from the material card and call it 219 panels. Conversely, 13 repeated intervals do not establish that a particular system fits the run or needs 13 purchasable panels. Its actual dimensions and layout have not been entered.
Why entering a very wide picket is not a workaround
A controlled software check changed the picket-width field to a hypothetical 96 in, kept zero gap and used a 100 ft run. The handler returned ceil(1200 ÷ 96) = 13. This matches the interval count above numerically, but the card still says Pickets / slats. The tool did not load a panel system or validate a panel width.
Other cards continued using their existing formulas. With 8 ft post spacing and 6 ft height, the same test returned 14 posts and 39 rails. Changing post spacing to 12 ft returned 10 posts and 27 rails while leaving the wide-infill count at 13. These are hypothetical code checks, not panel designs or quantities to order.
Changing a numeric input does not create the missing relationships between panels, posts and connectors. Do not use a large board-width value to disguise a supported input as an unsupported system estimator.
Information to keep with a separate panel takeoff
- The exact fence system and its documented panel dimensions.
- Whether a quoted width describes a panel itself, an opening or a post-to-post measurement.
- The actual run layout, including endpoints, changes of direction and gate positions.
- The system's component list, rather than generic rail and fastener counts copied from this tool.
- Any documented rules for shortened sections or other adjustments relevant to that system.
This is a missing-information checklist, not an installation specification. This page does not supply manufacturer dimensions, a prefab order, a price list or a new calculator mode.
Use each result within its own scope
For the implemented loose-infill equation, read how this calculator counts pickets. For the meaning of the wood selector, read why the two wood choices use the same formulas. The section and post output has its own post-count explanation.
Keep those planning outputs distinct from a product-specific panel takeoff. Neither the homepage nor its functionality has been changed to claim prefab-panel support.
Method and source
The supported options and actual material cards come from this site's form and calculation code. The interval comparison is original hypothetical arithmetic. The three length checks and two wide-input controls test that implementation; they do not measure a real property or certify a fence system.