𧱠Concrete Calculator
Calculate cubic yards for slabs, footings, and cylinders. Includes waste factor.
Quick Formulaβ
Rectangular Slabβ
Cubic Yards = (Length Γ Width Γ Depth) Γ· 27
Where depth is in feet
Cylinder/Roundβ
Cubic Yards = (Ο Γ radiusΒ² Γ depth) Γ· 27
Common Calculationsβ
| Pour Type | Typical Depth | Notes |
|---|---|---|
| Sidewalk | 4" | Light duty |
| Driveway | 4-6" | Residential |
| Garage slab | 4" | With thickened edge |
| Foundation | 8-12" | Check engineering |
| Footing | 12-24" | Per structural plans |
Waste Factorβ
Always add 5-10% for waste:
- Uneven subgrade
- Spillage
- Over-excavation
- Forms not perfectly square
Order Right
It's better to have a bit extra than to run short. A short pour can compromise the entire placement.
Bags vs. Ready-Mixβ
| Amount | Recommendation |
|---|---|
| < 1 yard | 80lb bags (45 bags/yard) |
| 1-3 yards | Consider ready-mix |
| > 3 yards | Ready-mix truck |