concrete calculator
Find volume from length, width and depth.
Formula
V = length × width × depth × (1 + allowance/100)
Length: 12 ft · Width: 9 ft · Depth: 4 in · Cubic meters ≈ (12 ft × 0.3048 m/ft)×(9 ft × 0.3048 m/ft)×(4 in × 0.0254 m/in)×(1+(5)÷100) · Cubic yards ≈ (1.070376801)÷0.9144^3 · Cubic feet ≈ (1.070376801)÷0.3048^3
How to use
- Measure the rectangular area.
- Enter depth and any allowance.
- Read the volume in three units.
Examples
- 3 × 3 × 3 feet = 1 yd³ = 27 ft³.
Frequently asked questions
Does this calculate a concrete mix?
No. It estimates slab volume; mix design, strength and reinforcement are separate.
What about irregular areas?
Split the area into rectangles and add their volumes.
Is the allowance automatic?
No. The displayed percentage is editable; use zero for geometric volume.
Sources
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