Post Hole Calculator
50lb Fast-Set Bags
0
Most common for fences
80lb Regular Bags
0
Concrete Volume (Cu. Ft.)
0
Post Displacement
0%
Hate mixing concrete?
Check Sika Foam Prices →Concrete Estimation for Fence Posts
Setting fence posts requires precise material calculation. If you simply calculate the volume of the hole, you will overbuy concrete because you aren’t accounting for the Displacement of the wood post itself.
What is Displacement?
A standard 4×4 post takes up significant volume inside the hole. Our calculator automatically subtracts the wood volume from the hole volume to give you the “Net Concrete” required. This typically saves 1-2 bags per hole compared to basic math.
Bags vs. Expanding Foam
For standard fences, Fast-Setting Concrete (50lb) is the standard. You pour it dry and add water. However, for difficult access areas, consider Sika Post Fix (linked above). One lightweight bag of foam replaces two 50lb bags of concrete and sets in 3 minutes.
Sika Post Fix (No Mix)
The lazy way: Pour it in, it expands and hardens in 3 minutes. No water, no heavy bags.
Check Price on Amazon → 
Kapro Magnetic Post Level
Essential: Straps to the post so you can use both hands to pour concrete. Don't build crooked fences.
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Seymour Post Hole Digger
The Clam Shell: Rugged fiberglass handles. Digs deep holes without snapping.
Check Price on Amazon →