BuildRight

Fence Calculator

Fence length divided into sections by post spacing — one more post than the number of sections.

Fence length (ft)

Post spacing (ft)

Posts needed

Standard post spacing is 6-8 feet — shorter spacing costs more but adds stability.

Fence sections: 19

What you entered

Fence length (ft): 150Post spacing (ft): 8

1
Number of fence sections
⌈150 ÷ 8⌉= 19 sections
2
Posts needed (one more than the number of sections)
19 + 1= 20 posts

Result

Posts needed: 20

150 ft of fencing at 8 ft spacing needs 20 posts across 19 sections.

Fence posts needed by fence length and post spacing

Each count divides the fence length by the post spacing, rounds up to whole sections, and adds one post to close the far end, which is exactly what the calculator does. These are line posts along a single straight run.

Fence length (ft)	Posts at 6 ft spacing	Posts at 8 ft spacing	Posts at 10 ft spacing
50	10	8	6
75	14	11	9
100	18	14	11
120	21	16	13
150	26	20	16
200	35	26	21
250	43	33	26
300	51	39	31
400	68	51	41

Line posts only. Every corner adds a post, every gate needs two heavier posts set deeper, and a double gate needs three, all on top of these counts. Run the calculation separately for each straight side of a yard rather than entering the whole perimeter at once, or the corners get counted wrong. Spacing follows the fence: 6 ft for wood privacy fences and windy sites, 8 ft as the standard for pre-made panels, 10 ft for chain link. Bury about a third of the post length, and below the frost line where the ground freezes, which is 36 to 48 inches in northern states. Check your property line and any local height or setback rules before digging, and call the utility locate service first.

Corner and gate posts need extra strength

This calculator gives a straight-line post count — corner posts, gate posts, and end posts typically need to be larger or set deeper than the standard line posts in between, since they bear more load.

Spacing affects both cost and stability

Closer post spacing (6 ft) costs more in posts and labor but creates a sturdier fence; wider spacing (8 ft) is cheaper but requires stronger, more rigid fence panels or rails to avoid sagging.

Frequently asked questions

My fence line is 150 ft long with posts every 8 ft — how many posts do I need?

20 posts (150 / 8 = 18.75 sections, rounded up to 19 sections + 1 = 20 posts). Remember that corners and gate openings each need additional posts beyond this straight-line count.

What spacing should I use for fence posts?

6-ft spacing is sturdier and better for wood privacy fences in windy areas. 8-ft spacing is the standard for pre-made fence panels and is more economical. Chain link fences typically use 10-ft post spacing.

How deep should fence posts be set?

General rule: bury 1/3 of the total post length. A 6-ft fence on an 8-ft post should be buried 2 ft deep. In areas with frost heave, posts should extend below the frost line (typically 36-48 inches in northern climates).

Do I need to add extra posts for gates?

Yes. Each gate opening needs two gate posts (which should be larger and set deeper than line posts), and these are in addition to the line post count this calculator provides. Double gates need three posts minimum.