How to order concrete for a small project
Turn slab area and thickness into bags or cubic yards, compare delivery options, and prepare the questions your concrete supplier needs.
Turn area and thickness into an order
Start by measuring the project footprint on the satellite map. Then use the planned slab thickness to calculate volume. Square footage alone cannot tell you how much concrete to buy.
For a hypothetical 12 × 12 ft slab at 4 inches thick, the calculation is 144 × (4 ÷ 12) = 48 cubic feet, or about 1.78 cubic yards. With a 10% allowance, that becomes 1.96 cubic yards. The thickness and allowance illustrate the math; use the requirements for your project.
| Order format | Example quantity | Confirm before buying |
|---|---|---|
| Ready-mix | 1.96 cu yd | Supplier’s order increments, minimum, and delivery terms. |
| 80 lb bags yielding 0.60 cu ft | 88 bags | The selected product’s mixed yield. |
| 60 lb bags yielding 0.45 cu ft | 118 bags | Yield, not just the weight on the bag. |
Those bag yields match QUIKRETE Concrete Mix 1101. Other mixes may differ. The allowance is already included; do not add it a second time. Calculate thickened edges or footings separately and include them in the total rather than relying on extra percentage to cover them.
Compare the work as well as the price
Bagged mix can suit a small, manageable pour. Compare it with ready-mix when the bag count becomes a handling or scheduling problem. There is no single yardage where one option is always cheaper.
Our example requires 88 of the 80 lb bags—7,040 lb of dry material, before mixing water. That means transport, unloading, repeated mixer batches, and someone placing and finishing while mixing continues. Check vehicle load ratings; buying the material and moving it are separate problems.
Compare the bag total plus transport and mixer rental with a delivered ready-mix quote, including short-load charges, waiting time, and any pump or other placement equipment. Ask who provides each item instead of assuming the truck price includes the whole job.
Have these answers ready for the supplier
- What is being built? Describe the use, dimensions, specified strength, reinforcement, and exposure to freezing or deicing salts. Share the project specification when there is one.
- How will it be placed? Confirm truck access and chute reach. If a pump or wheelbarrows are needed, arrange them before booking.
- How much and when? Give the calculated volume, allowance, delivery address, and preferred time. Confirm the final order quantity and cancellation terms.
- Who is ready on arrival? Name the person directing the delivery and the people placing and finishing. Ask how much unloading time is included.
Let the supplier match the mix to the stated requirements. Do not order only by a strength number or casually add water to make concrete easier to move; extra water can weaken the finished work.
Prepare for the pour—and the days after it
Before delivery, have the prepared base, forms, reinforcement, drainage slope, tools, and crew ready for the specified installation. Check local permit and inspection requirements before scheduling work. In the U.S., contact 811 before excavation and follow the local clearance process.
Curing is not simply letting concrete dry. Plan how you will retain moisture and protect the surface after finishing. NRMCA describes a typical curing period of 3–7 days, with the project specification controlling. Confirm the method, duration, and when the slab may carry its intended loads; a dry-looking surface is not that answer.
Have the product’s protective equipment ready. Fresh concrete can burn skin and eyes: wear suitable waterproof gloves and boots, eye protection, and clothing that keeps it off your skin.