Estimate how much concrete you need for cylindrical, square or rectangular pier foundations before you mix or order. Enter pier size, depth and quantity, add an optional waste allowance, compare cubic feet, cubic yards and cubic metres, estimate bag quantities from a manufacturer yield, and build a quick material-only cost estimate. The calculator also includes a round pier plus base option for projects that use a wider circular bearing pad beneath the pier.
All numeric entry fields start at 0. Select the shape that matches the concrete you actually plan to place, enter valid dimensions, then press Calculate Pier Concrete.
Your result will appear here after you press Calculate Pier Concrete.
The PDF includes pier type, dimensions, quantity, base volume, waste allowance, rounded order volume, cubic metres, optional bag estimate and concrete-only cost.
A round pier is a cylinder. Convert the diameter from inches to feet, divide by two for the radius, calculate π × radius² × depth, multiply by the number of piers, then divide cubic feet by 27.
The tool keeps concrete quantity separate from structural design. It shows the geometry, planned order volume, optional bag count and material-only cost from the dimensions you enter.
See the exact geometric volume before conversion to larger ordering units.
Compare the pier quantity with ready-mix concrete order volumes.
Add a practical allowance for drilled holes, excavation variation or handling losses.
See the same foundation concrete quantity in metric volume.
Apply your own local rate per cubic yard for a material-only estimate.
Save the main pier dimensions and volume estimate for project planning.
A concrete pier foundation estimate begins with the shape of the concrete. Round drilled piers are cylinders, square piers are rectangular prisms with equal sides, and rectangular piers use width × length × depth. Once the volume of one pier is known, multiply by the number of identical piers. The calculator converts the result from cubic feet to cubic yards and cubic metres automatically.
The mathematical part is straightforward, but foundation design is not. Pier diameter, depth, spacing, reinforcement and bearing area can depend on structural loads, soil conditions, groundwater, frost, uplift, lateral forces and applicable building codes. This page therefore treats the dimensions as inputs rather than recommending a structural pier size.
Volume (ft³) = π × Radius² (ft) × Depth (ft) × Quantity
If pier diameter is entered in inches, divide by 12 to convert the diameter to feet, then divide by two to get the radius. A 12-inch pier has a 1-foot diameter and a 0.5-foot radius. At 4 feet deep, one pier contains approximately 3.142 ft³, which is about 0.116 yd³.
| Round Pier | Depth | Volume Per Pier | 10 Piers | 20 Piers |
|---|---|---|---|---|
| 8 in Diameter | 4 ft | 0.052 yd³ | 0.517 yd³ | 1.034 yd³ |
| 10 in Diameter | 4 ft | 0.081 yd³ | 0.808 yd³ | 1.616 yd³ |
| 12 in Diameter | 4 ft | 0.116 yd³ | 1.164 yd³ | 2.327 yd³ |
| 16 in Diameter | 4 ft | 0.207 yd³ | 2.069 yd³ | 4.137 yd³ |
| 18 in Diameter | 4 ft | 0.262 yd³ | 2.618 yd³ | 5.236 yd³ |
| 24 in Diameter | 4 ft | 0.465 yd³ | 4.654 yd³ | 9.308 yd³ |
These values are geometry examples only. They do not imply that a particular diameter or depth is suitable for a deck, porch, house, pole building or other structure.
A square pier uses width × width × depth. Convert the width from inches to feet before multiplying. For example, an 18-inch square pier is 1.5 ft × 1.5 ft. At 4 ft deep, the volume is 9 ft³, or one-third of a cubic yard.
Volume (ft³) = Width (ft) × Width (ft) × Depth (ft) × Quantity
Rectangular piers use width × length × depth. They are useful to calculate when the concrete element is not circular and the cross-section has unequal sides. Convert both horizontal dimensions from inches to feet before multiplying by depth.
Volume (ft³) = Width (ft) × Length (ft) × Depth (ft) × Quantity
Some foundation details use a narrower vertical pier with a wider circular bearing base. The Pier + Round Base option calculates the vertical cylindrical pier and a separate circular base pad, then adds the two volumes. Enter the pier depth as the height of the cylindrical pier portion and the base thickness as the additional thickness of the wider pad so the same concrete is not counted twice.
Total = [π × Pier Radius² × Pier Depth] + [π × Base Radius² × Base Thickness]
A drilled or excavated hole is not always perfectly cylindrical. Soil can slough from the sidewalls, the bottom can become wider, groundwater can affect excavation, and loose material may change the actual volume. Form tubes can produce a more predictable shape above grade, while below-grade excavations can vary more.
This is why the calculator includes an editable waste or contingency field rather than assuming the mathematical volume will match the exact quantity placed on every site.
Cylindrical volume grows with the square of the radius. Doubling pier diameter does not merely double the concrete; it increases the cross-sectional area by four times before depth is considered. This makes accurate diameter measurement important when estimating many piers.
For example, a 12-inch diameter pier and a 24-inch diameter pier at the same depth have radii of 0.5 ft and 1.0 ft. The larger pier has four times the cross-sectional area and therefore four times the concrete volume.
Depth has a direct linear effect on volume. A 6-foot-deep pier contains 50% more concrete than a 4-foot-deep pier of the same diameter because 6 is 1.5 times 4. However, the correct depth is a structural and geotechnical decision, not a quantity optimization decision.
In cold climates, foundation depth can be affected by frost-protection requirements, but the exact requirement depends on location, building code provisions, soil, occupancy and project design. Do not select pier depth from a generic national chart. Confirm the approved design and local requirements before calculating the final concrete quantity.
The concrete volume calculation cannot determine whether a pier has enough bearing area. Soil bearing pressure and settlement are separate engineering considerations. A wider base can increase bearing area, but the dimensions must be established from the structural and geotechnical requirements of the project rather than from a volume calculator.
Deck and porch projects often use individual concrete footings or piers, but layout, diameter, depth and hardware depend on loads, span, post locations, frost and applicable residential code requirements. Once those dimensions are known, the round, square or pier-plus-base option can estimate the concrete volume quickly.
Post-frame buildings can use a variety of foundation details, including embedded posts, precast systems, concrete piers or pads. Do not assume that a generic pier calculator can choose the correct foundation system. Use the calculator only after the engineered or approved dimensions are known.
Structural piers supporting buildings can be subject to substantial axial, uplift and lateral forces. These are not DIY sizing decisions. The American Concrete Institute publishes concrete codes and foundation-related resources, while adopted building codes establish additional requirements. The calculator's role is limited to estimating the volume from known dimensions.
There is no universal waste percentage for pier foundations. Formed piers can be very predictable, while hand-dug or drilled holes may be less uniform. The appropriate allowance depends on excavation quality, number of piers, site access, spillage, pump or chute losses and supplier ordering increments.
A good workflow is to calculate the exact geometry first, inspect the actual holes, then add only the contingency that fits the site. The calculator keeps the base volume and the volume with waste separate so you can see the effect clearly.
When many piers are poured at once, ready-mix concrete may be practical because the total bag count can become large. Compare the calculated cubic yards with supplier minimum-load policies, delivery charges, access, discharge time and any pump requirement.
Bagged concrete can be convenient for a few small piers, especially where a truck cannot reach. To estimate bags accurately, use the finished yield printed for the exact product. If a bag yields 0.60 ft³ and the planned volume after waste is 12 ft³, the mathematical estimate is 20 bags.
Use our concrete bags to cubic yards calculator when you already know the bag count. For the reverse direction, use the cubic yards to concrete bags calculator.
Enter a concrete rate per cubic yard to get a material-only cost estimate. The calculator multiplies the rounded order volume by that rate. It does not include drilling, excavation, spoils removal, reinforcement, anchor hardware, form tubes, pump service, labor, inspections or engineering.
The Concrete Pier Foundation Calculator estimates concrete volume only. It does not calculate structural loads, allowable bearing pressure, settlement, pier reinforcement, anchor design, uplift, lateral capacity, frost protection, minimum embedment, concrete strength, durability exposure or code compliance.
For related estimating, see the concrete footing calculator, post hole concrete calculator, concrete volume calculator and concrete cost calculator.
Two piers can use the same concrete volume and still behave very differently depending on shape, depth, reinforcement, soil and load.
Gravity, uplift and lateral loads influence foundation design.
Soil strength and settlement are separate from geometric concrete volume.
Required depth depends on project and local conditions, not calculator convenience.
Rebar and anchorage must follow the applicable structural details.
These examples demonstrate volume only. They are not foundation sizing recommendations.
| Pier Example | Dimensions | Quantity | Base Volume | With 10% Allowance |
|---|---|---|---|---|
| Round Pier | 12 in Diameter × 4 ft | 10 | 1.164 yd³ | 1.280 yd³ |
| Round Pier | 16 in Diameter × 5 ft | 8 | 2.069 yd³ | 2.276 yd³ |
| Square Pier | 18 in × 18 in × 4 ft | 6 | 2.000 yd³ | 2.200 yd³ |
| Rectangular Pier | 18 in × 24 in × 4 ft | 4 | 1.333 yd³ | 1.467 yd³ |
| Round Pier + Base | 12 in Pier × 4 ft + 24 in Base × 8 in | 6 | 1.163 yd³ | 1.279 yd³ |
Answers about round and square piers, pier depth, concrete bags, waste, cost and foundation-design limits.
Convert the pier diameter from inches to feet, divide by two for the radius, then use π × radius² × depth × quantity. Divide cubic feet by 27 to convert the result to cubic yards.
A 12 inch diameter pier is 1 foot in diameter and 0.5 foot in radius. At 4 feet deep, one cylindrical pier contains about 3.142 cubic feet, or about 0.116 cubic yard before waste.
Yes. Enter the number of identical piers and the calculator multiplies the volume by that quantity.
Yes. The square pier option multiplies width × width × depth × quantity after converting the width from inches to feet.
Yes. Use the rectangular pier option and enter width, length, depth and quantity.
It adds the cylindrical pier volume to a separate circular base-pad volume for each pier. Enter the pier diameter and depth plus the base diameter and base thickness.
No. Pier diameter, depth, reinforcement, bearing area and spacing depend on loads, soil, frost, code and structural design. The tool estimates concrete volume only.
Yes. Enter a waste or contingency percentage and the calculator shows both the base volume and the volume after the allowance.
Yes. Enter the manufacturer-stated finished yield per bag in cubic feet. The calculator divides the planned volume by that yield and rounds up to whole bags.
Yes. Enter a local concrete rate per cubic yard. The material-only estimate does not include excavation, drilling, reinforcement, forms, pumping, labor or delivery fees.
That is a design and code question that depends on location and project requirements. Use the applicable building code, approved plans and qualified professional guidance rather than an online volume calculator.
Yes. After calculating, use the PDF button to save the pier type, entered dimensions, base volume, waste allowance, order volume, optional bag estimate and concrete-only cost.
Use current codes, approved project documents and authoritative concrete resources alongside any online volume estimate.
ACI publishes concrete codes, standards and foundation-related technical resources.
View ACI Foundation ResourcesTechnical standards, education, certification and concrete construction resources.
Visit ACIBuilding code resources used by jurisdictions for structural and foundation requirements.
Visit ICC Digital CodesWorkplace information about respirable crystalline silica hazards associated with concrete work.
Read OSHA GuidanceFoundation dimensions must come from the applicable design and code requirements. These external resources are for further reference; the calculator itself is a quantity estimator.