How concrete is ordered, delivered and priced
Concrete is bought by volume, not by weight or area. Knowing how suppliers sell it, and where the fees hide, turns a calculator result into a confident order.
Concrete is sold by volume
One cubic yard is 27 cubic feet. A 10 × 10 ft slab at 4 in thick is 33.3 cu ft, or about 1.23 yd³ before waste. Every calculator on this site converts your dimensions into cubic yards first, then into bags if you prefer.
Ready-mix from a batch plant
Ready-mix is mixed at a plant and delivered in a rotating truck, sold by the cubic yard. Suppliers usually set a minimum load, often around 1 yd³, and charge a short-load fee under it. A truck carries roughly 9–10 yd³, and the chute reaches about 10–15 ft from where the truck can park. Farther than that, plan for wheelbarrows or a concrete pump, which is booked and priced separately.
Bagged premix yields
| Bag size | Yield (approx.) | Bags per cubic yard |
| 40 lb | 0.30 cu ft | 90 |
| 60 lb | 0.45 cu ft | 60 |
| 80 lb | 0.60 cu ft | 45 |
Bags make sense up to roughly a cubic yard; beyond that, mixing time and labour outweigh delivery minimums. Follow the water ratio on the bag, because extra water weakens the mix.
Waste and margins
Order 5–10% more than the calculated volume. Uneven subgrades consume concrete faster than the drawings suggest, so check excavation depth at several points before the truck arrives.
Timing and weather
Unload promptly after arrival; suppliers expect it. Pour on unfrozen ground, and on hot, dry or windy days the mix stiffens faster, so have help and tools ready. Keep the finished slab damp for several days while it cures, following the mix guidance.
Questions to ask the supplier
- What strength (psi or MPa) does this use need — patios are commonly specified at 3,000–4,000 psi, but follow plans or local code
- What slump and aggregate size suit my pour
- What is the minimum load and the short-load fee
- How much time do I have on site before overtime charges
From order to calculator
Estimate the volume with the slab, footing, column, steps or post hole calculator, then compare truck delivery against bagged mixes with the bag calculator.
Reviewed by the MaterialWhiz Editorial Team. Last reviewed: October 10, 2026. See how we calculate · Report a correction.