Calculator
Fence Post Calculator
Work out posts, panels, rails and concrete bags for your fence run.
Verified August 2026
Posts needed
26 posts
25 sections at 8 ft spacing
- Panels / sections
- 25
- Rails
- 75
- Concrete bags (50 lb)
- 78 bags
- Estimated concrete weight
- 3,900 lb
Estimates only. Local pricing, site conditions and code requirements change the real number.
The formula
Posts = (length / spacing) + 1; Concrete per post = hole volume - post volume
Post holes should be about one-third of the post height deep and three times the post width wide. In Florida wind zones many jurisdictions require deeper setting for 6 ft and taller fences.
Worked example
A 200 ft fence at 8 ft spacing needs 26 posts, 25 panels and about 78 bags of 50 lb concrete at three bags per post.
Frequently asked questions
How deep should fence posts be?
Set posts one-third of the above-ground height deep, so a 6 ft fence uses a 2 ft hole minimum. High-wind Florida jurisdictions often require 2.5 to 3 ft for 6 ft fences.
How many bags of concrete per fence post?
Two to three 50 lb bags per post for a 4x4 in a 10-inch hole; three to four bags for a 6x6 or a deeper hole.
Sources
Sources & verification
Last verified August 2026. Cost figures are modeled estimates based on national baselines adjusted for local labor and material pricing — they are not quotes. Permit rules change; confirm with the building department before starting work.