Fence Posts: Concrete Guide
Space, dig and pour — with the concrete and bags sized for every post hole.
- 1
Lay out & space the posts
Mark the fence line and space the posts evenly — commonly 6–8 ft on-center. Count your posts; that's the number of holes.
- 2
Dig the post holes
Dig each hole about 3× the post width and one-third to one-half the post's above-ground height deep, below the frost line where it matters.
- 3
Set posts & pour the concrete
Brace each post plumb, then pour concrete around it. Enter the hole diameter, depth and count below to size the concrete and bags for the whole run.
- 4
Let it cure
Give the concrete 24–48 hours to set before hanging panels or applying load.
Fence post concrete calculator
For deck footings, fence posts and sonotube piers. Includes 10% waste.
Concrete for all holes
0.44 yd³
1.5 ft³ per hole
Bags of concrete (rounded up)
20
80 lb
27
60 lb
32
50 lb
40
40 lb
Volumes use standard bag yields and a 10% waste allowance; costs are national US averages that vary by region, mix and finish. See our methodology for exactly how each figure is worked out, or check the reference sources: