Concrete Volume Calculation Formula

Real Estate & Construction Formula • Published on July 30, 2026 • Last updated July 30, 2026

Mathematical Equation

$$\text{Volume (Cu Yds)} = \frac{\text{Length (ft)} \times \text{Width (ft)} \times \text{Thickness (in)}}{12 \times 27}$$

Variable Definitions

Length & Width

Slab or footing dimensions in feet

Thickness

Slab depth in inches

Detailed Explanation

In-Depth Guide

Concrete volume formula computes cubic yards or cubic meters of wet ready-mix concrete required to pour rectangular slabs, footings, steps, or columns.

How to Calculate: Step-by-Step

1. Convert thickness from inches to feet by dividing by 12. 2. Multiply Length (ft) × Width (ft) × Thickness (ft) to get cubic feet. 3. Divide cubic feet by 27 to convert to cubic yards (or multiply by 0.0283 for cubic meters). 4. Add 10% safety margin factor for spillage.

Worked Calculation Example

Slab 20 ft long, 15 ft wide, 4 inches thick: - Cu Ft = 20 × 15 × (4/12) = 100 cu ft. - Cu Yds = 100 / 27 = 3.70 cubic yards + 10% waste = 4.07 cu yds.

Common Use Cases

  • Driveway & patio slab pouring
  • Foundation footing estimation
  • Construction material ordering

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