Fence Calculator
Enter your fence length and post spacing to get the posts, rails, and pickets needed for the run.
This calculator gives an estimate for planning purposes only. Verify quantities and code requirements with a qualified professional before ordering materials or performing work.
How it's calculated
Posts
posts = ceil(fence length / post spacing) + 1
Divide the total run by post spacing, round up for a partial section, and add 1 for the starting post.
Rails
rails = sections × rails per section
Each section between two posts needs the same number of horizontal rails — 2 for a simple rail fence, 3 for taller privacy fencing.
Pickets
pickets = ceil((fence length in inches) / (picket width + gap))
Divide the total run in inches by the pitch (picket width plus the gap between pickets) to get the picket count.
Posts and rails by fence length (8ft spacing, 3 rails/section)
| Fence length | Posts | Rails |
|---|---|---|
| 50 ft | 8 posts | 21 rails |
| 100 ft | 14 posts | 39 rails |
| 150 ft | 20 posts | 57 rails |
| 200 ft | 26 posts | 75 rails |
Skip the manual math on your next takeoff
Struvia reads your plans and pulls quantities like this automatically — upload a plan and see it measure a real takeoff.
Fence Calculator FAQ
What post spacing should I use?
8ft is the most common spacing for wood fences. 6ft spacing is sturdier for taller privacy fences or windy areas; 10ft is sometimes used for lighter rail fencing to save on materials.
Does this account for gate openings?
No — measure gate sections separately and subtract them from your total fence length, since gates use different hardware than standard sections.
How many rails does my fence need?
2 rails is typical for a low rail or picket fence under 4ft. 3 rails is standard for 6ft privacy fencing to keep panels from bowing.