Most fence post holes will need between 1 - 4 bags of concrete to securely hold the post in place. The best way to determine the size of the hole is: Diameter of the hole is 3 times the width of the fence post. Depth of the hole is one-third to half the above ground height of the fence post.
How deep should a deck post be in the ground?
about 6 inches
What size footing do you need for a 6x6 post?
FOOTINGS: - Poured concrete footings should be a minimum of 8” wider than the posts (4x4 post – 12” min. width, 6x6 post – 14” min. width), a two level deck or deck with roof – 24”x24”. - The bottom of the footings must be a minimum of 36” below finish grade level.