How far apart should fence posts be?
For a wood fence with rails, as far apart as one rail is long, because each line post is centered where two rails meet.[1] With 8 ft rails the posts are 8 ft on center; shorter rails mean closer posts. Wire fences have published maximums:
| Fence | Maximum spacing | Source |
|---|---|---|
| Wood fence with rails | one rail length, posts centered where rails meet | [1] |
| Woven wire, conventional (hinge joint) | 14 ft | [2] |
| Woven wire, high-tensile fixed knot | 25 ft | [2] |
| Standard farm fence (Missouri spec) | 20 ft | [3] |
These are maximums. Corner, end and gate posts sit wherever the fence starts, stops or turns, and NRCS calls for corner bracing where the line changes direction by 25 degrees or more.[3]
How to space fence posts evenly
Divide the side by the maximum spacing, round up to whole sections, then divide the side by that number of sections.
on-center spacing = length ÷ (length ÷ maximum spacing, rounded up)
Example: a 75 ft side with an 8 ft maximum is 75 ÷ 8 = 9.4, so 10 sections. 75 ÷ 10 = 7.5 ft on center, with 11 posts. Equal spacing keeps every section the same width, so rails and panels can be cut to one length. The calculator does this for up to four sides and shares the corner posts.
| Length | 6 ft max | 8 ft max | 10 ft max |
|---|---|---|---|
| 40 ft | 8 posts · 5.71 ft | 6 posts · 8 ft | 5 posts · 10 ft |
| 75 ft | 14 posts · 5.77 ft | 11 posts · 7.5 ft | 9 posts · 9.38 ft |
| 100 ft | 18 posts · 5.88 ft | 14 posts · 7.69 ft | 11 posts · 10 ft |
| 150 ft | 26 posts · 6 ft | 20 posts · 7.89 ft | 16 posts · 10 ft |
| 200 ft | 35 posts · 5.88 ft | 26 posts · 8 ft | 21 posts · 10 ft |
Measuring on center
Spacing is measured on center: from the middle of one post to the middle of the next, not the gap between them. For a 3½ inch post set 8 ft on center, the clear opening between posts is 8 ft minus 3½ inches. Mark centers with stakes along a taut string before digging, and check the total against the fence length.
GatesTreat a gate as the end of one side and the start of the next: enter the fence on each side of the gate as separate sides, and add the gate posts.
Spacing, post depth and materials
Closer posts do not replace proper depth. Wood fence posts should be buried at least a third of their length and not less than 2 ft, below the frost line, on 4–6 inches of gravel.[1] For farm fences, NRCS sets line posts at least 24 inches deep for woven wire, and wood corner and brace posts at least 36 inches.[2] The fence calculator turns the same layout into rails, pickets and concrete, and the concrete page lists bags per cubic yard. Metric lengths use the exact foot of 0.3048 m.[4]
Frequently asked questions
How far apart should fence posts be for a 6 ft privacy fence?
One rail length, because line posts are centered where the rails meet.[1] With 8 ft rails, set posts 8 ft on center.
How far apart are posts on a woven wire fence?
NRCS Kentucky allows up to 14 ft for conventional woven wire and 25 ft for high-tensile fixed-knot wire.[2]
How many fence posts for 100 feet?
14 posts at an 8 ft maximum (7.69 ft on center), 11 at a 10 ft maximum, or 18 at a 6 ft maximum (5.88 ft on center).
Is fence post spacing measured on center?
Yes. Measure from the center of one post to the center of the next.