# Concrete Yield, Strength, and Mix Basics
Learn how many cubic yards you need, which PSI rating to specify, and how to order the right concrete mix.
Concrete is measured in cubic yards. A cubic yard covers approximately 81 square feet at a depth of 4 inches, and standard residential mixes are typically rated at 3,000–4,000 PSI. Calculate the required volume, then order 5–10% extra to account for uneven subgrade and waste.
How do I calculate how much concrete I need?
For a project-specific estimate, use the [concrete calculator for a slab](https://materialcalc.io/calculators/concrete/for/slab), the [concrete calculator for a sidewalk](https://materialcalc.io/calculators/concrete/for/sidewalk), or the detailed guide explaining [how much concrete you need](https://materialcalc.io/blog/how-much-concrete-do-i-need-calculator-guide).
Standard residential concrete is rated at 3,000–4,000 PSI. A 3,000 PSI mix is suitable for sidewalks and interior slabs. Driveways, garages, and structural footings should use concrete rated at 4,000 PSI or higher, with fiber reinforcement or rebar.
Ready-mix trucks usually require a minimum order, often 1 cubic yard, plus short-load fees for orders under 3 cubic yards. For jobs requiring less than half a cubic yard, bagged mix is more economical. An 80 lb. bag yields 0.6 ft³, so you'll need about 45 bags per cubic yard.
What is concrete used for?
- Slabs, driveways, patios, sidewalks
- Footings and foundation walls
- Steps, curbs, and pads
- Structural columns and piers
Which types of concrete are there?
What else do people ask about concrete?
How many bags of concrete in a yard?
About 45 × 80 lb bags, 60 × 60 lb bags, or 90 × 40 lb bags.
What PSI should a driveway be?
4,000 PSI minimum, with rebar or fiber and a 4–6″ compacted gravel base.
How much concrete for a 10×10 slab?
About 1.25 cubic yards at 4″ deep, or 1.55 yards at 5″.