Calculator Form
Use the responsive three-column layout on large screens, two columns on smaller screens, and one column on mobile devices.
Formula Used
| Shape | Formula | Notes |
|---|---|---|
| Slab / Patio / Driveway | Length × Width × Thickness × Count | Best for flat rectangular pours. |
| Wall | Length × Height × Thickness × Count | Useful for retaining walls and concrete panels. |
| Rectangular Footing | Length × Width × Height × Count | Use depth as height for footing volume. |
| Round Column / Pier | π × (Diameter ÷ 2)² × Height × Count | For cylindrical shafts, piers, and posts. |
| Circular Pad | π × (Diameter ÷ 2)² × Thickness × Count | Useful for round pads and small circular bases. |
| Unit Conversion | Cubic Yards = Cubic Feet ÷ 27 | All dimensions are converted to feet internally. |
How to Use This Calculator
- Select the project type that matches your pour shape.
- Enter each required dimension and choose the correct unit.
- Set the number of identical pours using the count field.
- Add a waste percentage to cover spillage and site variation.
- Optionally enter truck size and price per cubic yard.
- Press the calculate button to see results above the form.
- Review cubic feet, cubic yards, bags, trucks, and suggested order quantity.
- Use the CSV or PDF buttons to save a simple project report.
Example Data Table
| Project | Dimensions | Waste | Total Yardage |
|---|---|---|---|
| Driveway slab | 20 ft × 15 ft × 4 in | 10% | 4.07 yd³ |
| Continuous footing | 40 ft × 2 ft × 1 ft | 8% | 3.20 yd³ |
| Concrete wall | 30 ft × 8 ft × 8 in | 5% | 6.22 yd³ |
| Circular equipment pad | 12 ft diameter × 6 in | 8% | 2.26 yd³ |
| Round piers | 18 in diameter × 10 ft height × 4 count | 7% | 2.80 yd³ |
These examples are planning references only. Final field conditions, form tolerances, and supplier requirements can change the actual order quantity.
FAQs
1. How do I convert cubic feet to cubic yards?
Divide cubic feet by 27. One cubic yard contains 27 cubic feet. This calculator handles that conversion automatically after computing the selected shape volume.
2. Why should I add waste percentage?
Waste covers spillage, uneven subgrade, over-excavation, and small form changes. Many contractors add 5% to 10%, but the best value depends on your crew and site conditions.
3. Can I mix feet and inches in one calculation?
Yes. Each dimension has its own unit selector, so you can enter slab length in feet and thickness in inches without doing manual conversion.
4. Is this useful for ready-mix orders?
Yes. The suggested order rounds your result up to the next quarter yard, which is often more practical for ordering than using a long decimal.
5. Does reinforcement change the concrete volume?
Rebar, wire mesh, and fibers usually do not change the order quantity much. Large embeds, voids, or blockouts should be deducted separately when necessary.
6. Can I estimate bags instead of trucks?
Yes. The calculator shows estimated 60-pound and 80-pound bag counts using common yield assumptions. Actual yield can vary slightly by brand, mix, and water content.
7. What shapes are included here?
You can estimate slabs, walls, rectangular footings, circular pads, and round columns or piers. That covers many common residential and light commercial pours.
8. Should I round the result up before ordering?
Usually yes. Ordering slightly more is safer than running short during placement. Always review supplier minimums, delivery fees, and local mix availability first.