Concrete Yard Calculator
Ordering ready-mix by the truck? This calculator turns your slab dimensions into cubic yards and adds a waste factor so you do not come up short mid-pour. Most suppliers sell in quarter-yard increments and set a minimum, so round your order up.
Total volume required
7.82Cubic Yards
Cubic feet
211.20
Cubic meters
5.98
Bags (80 lb)
352
Estimate includes your waste factor. Figures are estimates, not a quote.
How to use this calculator
- 1Enter the length and width in feet and the thickness in inches.
- 2Apply a waste factor of 5–10%; concrete that goes over forms or into a soft subgrade is gone for good.
- 3Read the cubic-yard figure — that is what the ready-mix supplier needs.
- 4Round up to the next quarter yard when you place the order, and confirm any minimum load fee.
Formula & rounding
Cubic yards = (length × width × thickness in feet) ÷ 27, then × (1 + waste). One cubic yard fills 27 cubic feet — about an 81 sq ft area at 4 inches thick.
24 ft × 24 ft slab, 4 inches thick
- Volume = 24 × 24 × (4 ÷ 12) = 192 cubic feet
- With 10% waste: 192 × 1.10 = 211.2 cubic feet
- Cubic yards = 211.2 ÷ 27 = 7.82 cubic yards
- Round up for ordering → 8 cubic yards
= ≈ 7.82 cubic yards — order 8
How far one cubic yard goes by thickness
- 4 in thick: 27 ÷ (4 ÷ 12) = 81 sq ft per cubic yard
- 5 in thick: 27 ÷ (5 ÷ 12) = 65 sq ft per cubic yard
- 6 in thick: 27 ÷ (6 ÷ 12) = 54 sq ft per cubic yard
- Thicker pours cover less area, so a 6 in slab needs ~50% more yards than a 4 in one
= One cubic yard covers ≈81 / 65 / 54 sq ft at 4 / 5 / 6 inches
Ready-mix ordering checklist
Cubic yards are only half the order — plants batch, price, and deliver on their own rules. Walk these before you book a truck so the figure above turns into the right delivery.
| Step | Typical practice | Why it matters |
|---|---|---|
| Round up | To the next ¼ yard | Plants batch in quarter-yard increments — you cannot order 7.82 yd³ exactly, so 8 it is. |
| Minimum load | Often ~1 yd³ | Below the minimum you still pay the full minimum charge, so tiny pours may favor bags. |
| Short-load fee | Added under ~3–5 yd³ | Small loads carry a surcharge (commonly $50–$150) to cover the dedicated truck run. |
| Truck access | Chute reach ≈ 10–18 ft | No direct access means a pump or wheelbarrows — arrange it before the pour date. |
| Standby time | Free window, then per-minute | Have crew and forms ready; unloading delays are billed by the minute once the window closes. |
Estimate · unofficial. Increments, minimums, and fees vary by plant — confirm exact terms when you book.
Frequently asked questions
How do I calculate cubic yards of concrete?
Multiply length × width × thickness in feet to get cubic feet, then divide by 27. A 24 ft × 24 ft slab at 4 inches is about 7.1 cubic yards before waste, or about 7.8 with 10%.
How much area does a yard of concrete cover?
One cubic yard (27 cubic feet) covers about 81 square feet at 4 inches thick, 65 sq ft at 5 inches, and 54 sq ft at 6 inches. Thicker pours cover less area per yard.
How much extra concrete should I order?
Plan for 5–10% over your calculated volume. Running short means a second truck or cold joint, while a little extra is cheap insurance. Suppliers typically deliver in 0.25-yard increments.
What is the minimum ready-mix order?
Most plants set a minimum (often 1 cubic yard) and add a short-load fee below a few yards. If your project is under a yard, compare bagged concrete first.
Assumptions & sources
- Cubic yard
- 1 yd³ = 27 cu ft; suppliers typically order in ¼-yard increments.
- Waste factor
- Default 10% — ready-mix is hard to top up, so do not under-order.
- Ordering
- Minimum loads and short-load fees often apply below ~1 yd³; confirm with your supplier.
- Large orders
- Verify any order near or above 10 cubic yards before the pour date.
See the methodology & sources for how these values, formulas, and rounding are chosen.
Helpful concrete guides
- How to calculate concrete — walks the volume-to-cubic-yards math behind a ready-mix order, including the ÷27 step.
- Concrete bag sizes & yields — helps decide when a sub-yard job is cheaper to bag than to order by the truck.
This is an estimate, not a quote. Concrete quantities, bag yields, block coverage, and prices vary with product, brand, mix, region, supplier, tax, delivery, and on-site conditions. Always confirm with your supplier and round up for safety. For structural or code-related work, consult a qualified professional or your local building authority.