Split rail fence calculator
Calculate posts and horizontal rails for a two-rail or three-rail split rail or ranch-style fence.
Fence calculator
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Overview
Split rail (also called ranch-style) fencing drops picket infill entirely: horizontal rails run between posts and are the whole visible fence, so this calculator switches off the picket and panel fields for this material and counts only posts and rails.
Two-rail and three-rail are the two common configurations; three-rail is a taller, more solid-looking option and is also common for horse and livestock paddocks.
Common mistakes
- Using tight wood-picket-fence post spacing for split rail, which typically runs wider, commonly 8 to 10 feet, since there is no infill panel weight to support.
- Forgetting that switching from two-rail to three-rail changes the rail count per section, and therefore total rails, without changing post count.
- Counting rails as total run length instead of rails-per-section times sections.
Related calculators
- Horse fence calculator Plan a livestock-safe horse fence at the commonly cited 4.5 to 5 foot height, with post spacing and full material take-off.
- Fence post calculator Calculate line posts, corner posts and end posts from run length and spacing, with concrete for each post included in the take-off.
- Fence cost calculator Estimate total fence cost from run length, height and your local material and labor rates, with the budget math shown.
Related reading
In-depth guides
Frequently asked questions
What is the difference between two-rail and three-rail split rail fence?
Three-rail adds a middle rail for a taller, more solid look and slightly more containment, commonly used for horse paddocks. Both use the same post spacing and post count formula; only the rails-per-section count differs.
How do I calculate the number of rails?
Count the post sections first (fence length divided by spacing, rounded up), then multiply by the rails per section. Two-rail is 2 per section, three-rail is 3.
What post spacing should a split rail fence use?
8 to 10 feet on center is the common range, wider than a picket fence because split rail carries no heavy infill. Local or vendor guidance can narrow it for a specific rail product.
Is split rail a good dog or privacy fence?
Not for containment or privacy: rails are far apart, so it does not keep in a determined dog and does not block sightlines. It is a boundary and decorative fence, which is what it is built for.
How deep should split rail posts be set?
The same one-third rule applies: set about one third of the post length in the ground, and at least to the local frost line where ground freezes. The post depth calculator runs that for you.
Do split rail posts need concrete?
Generally not in the way a privacy fence does, because split rail carries less wind load, but corner and end posts take the tension of the rails and benefit from a solid footing or rammed earth. Local soil is the deciding factor.
Can split rail be built in materials other than wood?
Yes, vinyl and composite split rail systems are sold as kits, though the calculator's rail count logic applies regardless of material because the geometry is the same.
How much does a split rail fence cost?
Less than a privacy fence per foot because there is no infill material. Prices vary by species and region; enter your own local unit prices in this calculator for a total tied to your numbers.