Post Holes Calculator
Quantity = 1
Post Size =
Dimensions provided in inches so convert inches to feet then multiply by itself for square feet of surface: 2 inches round / 12 = 0.16666667 * 0.16666667 = 0.02777778
Bag Size = 0.15
Waste = 10
Estimates the total cubic yards of concrete needed for post holes factoring in the void from the post.
-Diameter: Diameter of the hole(s).
-Depth: Depth of the concrete.
-Quantity: Number of holes this same size.
-Post Size: Size of the post in nominal dimension. A 4"×4" post will be calculated with a void of the actual 3-1/2"×3-1/2" dimension.
-Bag Size: Size of the bag if using ready-mix concrete by the bag.
-Waste: Percentage to add to cover waste.
-Concrete: Estimated volume of concrete.
-#Bags: Number of bags of concrete.
Size of the hole can vary depending on many factors including materials used and the soil type. General rules of thumb would be to make the diameter three times the size of the hole. For example the diameter of the hole for a 4" post would be 12". The depth should be 1/3 of the height above ground. For a 6' fence, the hole should be 2' in depth.
Estimate the total cubic yards of concrete and 60lb bags of ready-mix concrete you will need to install fifty 6"×6" posts. You will place the post into a 16" diameter hole, 2' in depth. Use a waste factor of 5%.
-Post Size [in]: 6"×6"
-Bag Size: 60lbs
You will need 4.649yd³ of concrete and 277 bags.