Construction

Verified calculator with a transparent formula

Construction

Concrete Pier Calculator.

Estimates the volume of concrete needed for cylindrical piers and the total weight of concrete required.

Results update live as you type.
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Your inputs

How it works

  1. 1

    Measure the diameter and depth of one pier in feet.

  2. 2

    Calculate the cross-sectional area: π × (diameter/2)².

  3. 3

    Multiply the area by the depth to get the volume per pier.

  4. 4

    Multiply by the number of piers to get total concrete volume.

pi * (diameter / 2)^2 * depth * piers

Frequently asked questions

How do I convert cubic feet to cubic yards?

Divide the cubic feet by 27. For example, 100 ft³ is about 3.7 yd³.

What is the weight of concrete per cubic foot?

Standard concrete weighs about 150 pounds per cubic foot. This calculator uses that value.

Should I order extra concrete?

It's wise to order 5-10% extra to account for spillage, uneven ground, and variations in depth.

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Results

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Total Concrete Volume

—ft³

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Estimate for general guidance only — verify important decisions with an appropriate professional.

How it works

Estimates the volume of concrete needed for cylindrical piers and the total weight of concrete required.

  1. Measure the diameter and depth of one pier in feet.
  2. Calculate the cross-sectional area: π × (diameter/2)².
  3. Multiply the area by the depth to get the volume per pier.
  4. Multiply by the number of piers to get total concrete volume.

Formulas

The math behind this calculator, written out so you can verify the result.

Volume of a Cylinder

V = π × r² × h

The volume of a cylindrical pier is the area of its circular base (πr²) times its height (depth).

Example:

Input: r = 0.75 ft, h = 4 ft

Calculation: π × 0.75² × 4

Result: ≈ 7.07 ft³ per pier

Total Concrete Weight

W = V × 150 lb/ft³

Multiply the total volume by the density of concrete (about 150 lb/ft³) to estimate weight.

Example:

Input: V = 28.27 ft³

Calculation: 28.27 × 150

Result: ≈ 4,240 lbs

Real-world use cases

Where this calculation shows up in everyday life.

Deck Foundations

Determine concrete needed for deck piers to support posts and beams.

Example: A 12' x 16' deck with 6 piers.

Shed or Gazebo Bases

Calculate concrete for piers that support small structures.

Example: A 10' x 10' shed with 4 piers.

Post and Beam Construction

Estimate concrete for piers in post-and-beam framing.

Example: A barn with 8 piers.

Tips and common mistakes

Tips

  • Always measure the actual depth of the hole, not just the planned depth.
  • Add 10% extra concrete to your order to avoid running short.
  • Use a concrete calculator for irregular shapes or multiple sizes.
  • Check local building codes for minimum pier size and depth.

Common Mistakes to Avoid

  • Using diameter instead of radius in the area formula.
  • Forgetting to multiply by the number of piers.
  • Not accounting for concrete waste or spillage.

Assumptions and limitations

  • Use the stated inputs and units.
  • Results are estimates for planning and education.
  • Check measurements and source data before making an important decision.