How Much Concrete Per Fence Post?
Concrete is easy to under-order on a fence job because it hides in dozens of small holes. Here is the quick rule and the math behind it.
The burial rule
Set posts about one-third of their above-ground height into the ground (a 6 ft fence post is usually 8–9 ft long, buried ~2.5–3 ft). Dig the hole roughly three times the post width so there is a solid collar of concrete around it.
Bags per post
A 60 lb bag yields ~0.45 cubic feet. A typical 8-inch-wide hole at 2.5 ft deep is about 0.9 cubic feet — roughly two 60 lb bags. Gate and corner posts are set deeper and wider, so budget an extra bag each. The fence calculator totals the bags across all your posts automatically.
FAQ
How many bags of concrete per fence post?
Usually one to two 60 lb bags per line post, and two to three for larger gate or corner posts, depending on hole depth and width.
How deep should a fence post be?
About one-third of the post’s above-ground height, and below the frost line in cold climates — commonly 2 to 3 feet for a residential fence.
Do I need gravel at the bottom of the hole?
A few inches of gravel helps drainage and reduces rot on wood posts; it does not replace the concrete collar.