Concrete Guides & Reference Articles
Practical, field-tested reference guides — thickness charts, curing times, reinforcement choices, and cost breakdowns.
Guides & Reference Articles
How Much Concrete Do I Need? A Complete Guide
The full method estimators use to size any pour, with worked examples.
Read Guide → GUIDEHow Thick Should a Concrete Slab Be?
Thickness guidance by use case: sheds, patios, driveways, and garages.
Read Guide → GUIDEConcrete Curing Time: What to Expect
How long concrete takes to set, cure, and reach full strength.
Read Guide → GUIDERebar vs. Wire Mesh: Which Reinforcement to Use
When to reinforce with rebar, mesh, fiber, or both.
Read Guide → GUIDESonotube Sizing Guide
Picking the right tube diameter and depth for piers and posts.
Read Guide → GUIDEDriveway Concrete Cost Breakdown
What a concrete driveway actually costs, line by line.
Read Guide → GUIDEConcrete vs. Cement: What's the Difference?
Clearing up the most common terminology mix-up in the trade.
Read Guide →Frequently Asked Concrete Questions
Direct reference answers compiled for job-site use.
One cubic yard is 27 cubic feet and an 80 lb bag yields about 0.6 cubic feet, so it takes about 45 bags with no waste. Because job-site ground is rarely perfectly level, many people buy 5–10% more, roughly 48–50 bags, to avoid running short mid-pour.
A 10 ft × 10 ft slab at 4 inches deep equals 33.3 cubic feet, or about 1.23 cubic yards with no waste. That is roughly 56 bags of 80 lb mix or 75 bags of 60 lb mix. With a 10% waste buffer it becomes about 1.36 cubic yards, or 62 bags of 80 lb mix.
For pours over about 1 cubic yard (roughly 40–45 bags), a ready-mix truck is almost always faster and cheaper per yard than bagging, once you factor in labor. Smaller pours — post holes, small patches — are usually more practical with bags.
Ready-mix concrete often runs roughly $150–$200 or more per cubic yard, depending on region and mix design. Deliveries under about 4–5 cubic yards commonly carry a short-load fee, often $75–$150 or more. Ask your local supplier for a current quote.
10% is the standard default for most flatwork. Use 5% for very controlled, form-boarded pours, and 15–20% for uneven ground, hand-dug footings, or irregular shapes where over-excavation is likely.
No — reinforcement steel displaces a negligible amount of volume and is not subtracted here. The waste factor built into each calculator already covers this along with minor sub-base and form variance.