スプリットレール計算ツール

Split rail, also called ranch-style fencing, drops picket infill entirely: horizontal rails run between posts and are the entire visible fence, which is why this calculator switches off the picket and panel fields for this material and counts only posts and rails. It is a different kind of take-off from the picket-based wood styles on this site: there is no board width or gap to set, only post spacing, rail count per section and total run length.

Two-rail and three-rail are the two common configurations, and the choice is about height and look rather than strength for a basic boundary: three-rail adds a middle rail for a taller, more solid appearance and a bit more containment, which is also common on paddock fencing covered on the horse fence calculator. Both configurations use the same post spacing and post count formula; only the rails-per-section number changes, so switching between them does not change how many posts you buy, only how many rails.

Post spacing on split rail typically runs wider than a picket or privacy fence, commonly 8 to 10 feet on center, since there is no infill panel weight or wind load from solid boards to support. The fence post calculator is useful for checking that spacing and post count independent of the rail configuration, and the fence post depth calculator confirms hole depth against the local frost line, which still applies to split rail posts even though they carry less load than a solid fence.

Materials cost less per foot than a privacy or picket style simply because there is no infill to buy; the fence cost calculator turns the post and rail counts from this page into a total using your own local prices. For general paddock and pasture fencing context beyond just split rail, horse and livestock fencing basics covers the broader options, and the fence materials guide compares split rail to other wood styles for anyone still deciding on a look before ordering rails.

Corner and end posts on a split rail fence take the tension of the rails pulling against them, which is different from a line post simply supporting the spans on either side, so a solid footing or rammed earth at the corners matters even on a style that generally needs less concrete than a privacy fence. Local soil conditions are usually the deciding factor in how much footing a given post actually needs, more than any fixed rule.

Because split rail carries no infill panel, it is not a containment or privacy fence: the wide gaps between rails do not block sightlines and will not reliably hold in a small or determined dog, which is why it functions as a boundary and decorative style rather than a security fence. Choosing split rail is usually a statement about the look of the property line rather than a functional requirement to keep something in or out, and that distinction is worth confirming before ordering materials for a use the style was not built for.

Rail material matters for how the fence is actually assembled: round or half-round rails taper and fit into routed holes in the posts, while square-sawn rails typically sit in dadoed notches, and the two systems are not interchangeable without matching posts drilled or cut for that specific rail profile. Confirming which profile a given rail product uses before ordering posts avoids a mismatch between the two halves of the same fence.

Split rail is also commonly run across uneven or rolling terrain without the racking or stepping decision a solid privacy fence requires, since individual rails can follow a gentle grade change between posts without the same visual gap issues a solid board run would show. That makes it a practical choice for a long rural boundary where the ground is not perfectly level, in addition to being the lower-cost option in a straight material comparison.

Split rail is also one of the few wood styles commonly extended with wire mesh or electric wire strung along the rails when some containment is needed without giving up the open ranch-style look, a common approach on properties that want the split rail appearance along a road frontage while still needing to keep livestock or a dog contained. Adding wire does not change the post or rail count this calculator returns, since it attaches to the existing rails and posts rather than requiring its own structure, but it does add a separate materials line that is worth pricing on its own.

End posts on a split rail run sometimes use a larger diameter than line posts specifically because they anchor the rail ends under tension, a detail worth confirming with whatever rail product is being used, since some manufactured rail systems specify a minimum end-post size that differs from their line-post recommendation.

Because the posts are the main structural element on a split rail fence, upgrading to a slightly larger post diameter at corners and gate posts is a low-cost way to add durability without changing the rail count or the overall material list this calculator returns.