Concrete Footing Calculator

What Is a Concrete Footing Calculator?

Concrete Footing Calculator is a purpose-built tool designed to accurately calculate the amount of concrete needed to fill various footing shapes like round, square, or rectangular forms. Whether constructing a deck, installing a fence, or pouring a foundation, this tool helps you avoid costly guesswork and material shortages.

Key benefits:

• Saves time on-site
• Prevents over-/under-ordering of concrete
• Eliminates manual math errors
• Offers real-time adjustments for multiple footings

Target Users: Who Needs This Tool?

This calculator is ideal for:

• Deck builders are setting support posts or piers
• Fence contractors preparing post holes
• General contractors calculating materials for residential/commercial foundations
• DIY homeowners planning small projects like pergolas or sheds

Types of Footings Supported in the Concrete Footing Calculator

Round Footings (Deck Piers, Columns)

These are most common for supporting vertical loads like porch posts or pergola legs. Calculations use the formula for the volume of a cylinder, based on the diameter and depth.

Square Footings (Posts, Structural Bases)

These are often used under light poles or foundation piers. They use side length × side length × depth to determine volume.

Rectangular Footings (Wall and Beam Foundations)

Ideal for structural foundation walls and beams. You’ll need to input the length, width, and depth for each footing.

Step-by-Step Guide to Using the Concrete Footing Calculator

Step 1: Select Footing Shape

Pick one of the following options:

• Round (column, sonotube, pier)
• Square (post bases)
• Rectangular (walls, beams)

Step 2: Enter Dimensions (in Inches)

Input precise dimensions for each shape:

• Diameter (for round)
• Side length (for square)
• Length × Width (for rectangular)
• Depth (vertical measurement for all)

Step 3: Add Quantity

Specify how many identical footings are needed. The calculator multiplies accordingly.

Step 4: Review Instant Results

The output provides:

• Volume per footing
• Total volume (in cubic inches, feet, and yards)
• +10% overage to account for spills, voids, and inconsistencies

Concrete Footing Volume Formulas Explained

Round Footing Volume Formula

Volume = π × (Diameter/2)² × Depth

Square Footing Volume Formula

Volume=Side×Side×Depth

Best used for single-post footings or symmetrical bases.

Rectangular Footing Volume Formula

Volume=Length×Width×Depth

Common for foundation strip footings.

Output Measurements and Units Conversion

Cubic Inches to Cubic Feet

There are 1,728 cubic inches in a cubic foot. So, volume in cubic inches ÷ 1,728 = cubic feet.

Cubic Feet to Cubic Yards

There are 27 cubic feet in one cubic yard. So, volume in cubic feet ÷ 27 = cubic yards.

Expert Tips for Perfect Footings

• Excavation and Gravel Base
  • Always dig 6 inches deeper than your planned depth for a compacted gravel base, improving drainage and stability.
• Using Sonotubes for Round Forms
  • Sonotubes ensure uniform diameters. Use them for decks and fences to maintain clean, upright concrete columns.
• Ready-Mix vs. Pre-Mix Concrete
  • Use ready-mix trucks for 10+ footings.
  • For smaller jobs (under 5 footings), 60- or 80-lb bags of pre-mix are more manageable.