Concrete Pier Calculator
Estimate concrete for cylindrical piers with optional widened bases, including volume, full bags, placed weight and ready-mix cost.
Default project preview
1.37 yd³
Concrete bags
62
Shaft volume
1.24 yd³
Bell-base extra
0 ft³
Total drilled depth
24 ft
Calculator
Build the material order
Your order will appear here
Enter the project details and calculate a rounded material estimate.
Input and output guide
What each value means
The labels and units below are part of this calculator’s visible methodology. Replace every default with measurements or product data from the actual project.
Pier diameter
Enter this project assumption in in. The current imperial default is 16 in.
Pier depth
Enter this project assumption in ft. The current imperial default is 4 ft.
Number of piers
Enter this project assumption in a unitless value. The current imperial default is 6. Minimum: 1.
Base-bell diameter
Enter this project assumption in in. The current imperial default is 16 in.
Base-bell thickness
Enter this project assumption in in. The current imperial default is 0 in. Minimum: 0.
Extra allowance
Enter this project assumption in %. The current imperial default is 10 %. Minimum: 0. Maximum: 50.
Concrete yield per bag
Enter this project assumption in ft³. The current imperial default is 0.6 ft³.
Ready-mix price
Enter this project assumption in per yd³. The current imperial default is 165 per yd³. Minimum: 0.
Price per bag
Enter this project assumption in a unitless value. The current imperial default is 7. Minimum: 0.
How to read the outputs
Concrete bags
rounded full bags. Default preview: 62.
Shaft volume
cylindrical shafts. Default preview: 1.24 yd³.
Bell-base extra
beyond shaft diameter. Default preview: 0 ft³.
Total drilled depth
all piers. Default preview: 24 ft.
Placed weight
planning density. Default preview: 5,523 lb.
Cost comparison
ready-mix / bags. Default preview: $225.26 / $434.00.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Shaft volume = π × radius² × depth × quantity. Optional bell volume adds only the widened area beyond the shaft. Allowance is applied before bag rounding.
Reviewed project guidance
How to use this estimate in a real project
Last reviewed: July 30, 2026
Estimate concrete for cylindrical piers from diameter, depth, quantity and waste allowance.
Calculation steps
- 1Enter the actual project dimensions or operating values.
- 2Apply the calculator formula using consistent units.
- 3Review the unrounded result and the editable allowance.
- 4Round only to the product, stock length or equipment increment actually purchased.
Worked numerical example
Six piers 12 in diameter and 4 ft deep require about 0.70 yd³ before waste.
Purchasing and rounding
Multiply one cylindrical pier volume by the actual pier count, then add only a documented placement allowance. For bagged concrete, convert the final volume using the bag's published yield and round up to whole bags; for ready-mix, use the supplier's delivery increment.
Interpret the result
The result is concrete volume for cylindrical shafts of the entered diameter and depth. Bell bottoms, enlarged footings, over-excavation and irregular augered holes are extra volume and should be measured or allowed for separately rather than hidden in the pier diameter.
Page-specific assumptions
- Inputs describe one consistent project condition.
- Entered yields and efficiencies match the selected product or equipment.
- Site-specific code and engineering requirements are checked separately.
Common mistakes
- Mixing imperial and metric inputs.
- Using nominal dimensions where actual coverage controls.
- Rounding intermediate values too early.
- Treating a quantity estimate as design approval.
Primary and technical references
BuildMeter provides planning estimates, not engineering, architectural, electrical, mechanical, plumbing, permit or code approval. Review the methodology and verify final decisions with product documentation and qualified professionals.
FAQ
Concrete Pier Calculator questions
Is a concrete pier the same as a post hole?+
The geometry can be similar, but structural piers may carry significant loads and require engineered diameter, depth, reinforcement and bearing.
How is an optional bell base counted?+
Only the widened portion beyond the shaft diameter is added, avoiding double-counting the shaft through the bell thickness.
Does this account for soil falling into the hole?+
The allowance can cover modest irregularity, but unstable excavations may need casing, forms or a larger contingency.