How far apart should fence posts be?

Wood and vinyl fences are typically set 6–8 feet on-center; closer spacing adds strength in windy areas.

How much concrete per post?

A standard post hole takes about 1.5–2 bags of fast-setting concrete depending on depth and diameter.

Fence Calculator

Estimate posts, panels, rails and concrete for a fence run.

100% free to useNo sign-up requiredImperial & metric units

How many fence posts and pickets do I need?

Divide the fence length by your post spacing to get sections, then add one for the number of line posts. A 120 ft fence at 8 ft spacing needs 15 sections and 16 posts, plus corner and gate posts. Plan two bags of concrete per post and three rails per section on fences 6 feet and taller.

Inputs

Fence lengthft

Fence type

Post spacing

Fence heightft

Corner postscount

Gatescount

Waste allowanceApplied to material quantities

Results

Posts

8 ft on-center

Sections

Concrete Bags

2 per post

Gate Hardware

1 sets

Rails

Pickets

240

Estimates update instantly as you type. Confirm against local code before ordering materials.

A fence is a long run of repeating parts, which makes it easy to under-order posts or rails by a single unit and stall the job. This calculator takes the total run, your post spacing, and the fence height to return posts, sections, rails, pickets, and the bags of concrete needed to set the posts.

Post spacing and height drive nearly everything: taller fences need a third rail, and tighter spacing means more posts and more concrete. The result gives you a full material takeoff for a straight run, which you adjust for corners, gates, and grade changes on your specific layout.

How fence materials are estimated

Post count is the total fence length divided by the post spacing, plus one for the end post. Panels or pickets fill the bays between posts, and each post is set in concrete.

Posts = (Fence Length ÷ Post Spacing) + 1

Fence posts by length at 8 ft spacing

Line posts and concrete for a straight run, before corners and gates.

Fence length	Sections	Line posts	Concrete bags
50 ft	7	8	16
100 ft	13	14	28
150 ft	19	20	40
200 ft	25	26	52

Add a post at every corner and on each side of a gate beyond the straight-run count.

How to use it

1Enter the total fence length in feet.
2Set the post spacing (8 ft on-center is standard).
3Enter the fence height for rail and picket counts.
4Review posts, rails, pickets and concrete bags needed.

Key terms explained

Section: The span of fence between two posts. Section count plus one equals the number of posts.
On-center spacing: The distance between post centers, typically 6 or 8 feet for wood fences.
Rail: The horizontal members that carry the pickets. Fences 6 feet and taller usually need three.
Picket: The vertical face boards. Count depends on picket width and any spacing between them.

Worked examples

Backyard fence

A 120 ft fence at 8 ft spacing needs 16 posts and about 15 panels.

Side yard

A 48 ft run uses 7 posts, 6 panels and roughly 14 bags of concrete.

Pro tips from the field

1Set posts at least one-third of their above-ground height into the ground for stability.
2Add a post at every corner and on each side of a gate beyond the straight-run count.
3Use two bags of concrete per post as a baseline; widen holes in sandy or wet soil.
4Step or rack panels on slopes; do not assume a flat-run count holds on grade.

Common mistakes

Spacing posts too far apart, causing rails to sag.
Forgetting gate posts need extra concrete and bracing.
Not adjusting picket counts for the gap between boards.

Where it gets used

Material takeoffs

Generate a full post, rail, and picket list for a straight run in seconds.

Concrete planning

Know how many bags to buy so you set every post in one trip.

Client quotes

Price fencing jobs fast with consistent, defensible quantities.

Frequently asked questions