Concrete Slab Cost Calculator
Use this concrete cost calculator to estimate cubic yards, bag counts, waste allowance, delivery fees, and material budget for slabs, patios, garages, footings, and other US projects.
Concrete slab cost calculator: what is included?
The result separates base volume from the suggested order quantity, then applies your waste allowance before calculating material cost. Delivery or short-load charges and optional project costs are shown separately so a material estimate is not mistaken for a contractor quote.
For a complete slab budget, also plan for compacted base material, forms, reinforcement, control joints, finishing tools, permits where required, and labor. BuildCalc does not provide structural design or a binding supplier price.
Concrete prices in the US
| Purchase method | Typical price range | Best for |
|---|---|---|
| Ready-mix concrete | $125–$195 per cubic yard delivered | Slabs, driveways, footings over 1 cu yd |
| 80 lb bag concrete | $4–$7 per bag | Small repairs, post holes, walkways under 1 cu yd |
| 60 lb bag concrete | $3–$6 per bag | Small patches, fence posts, curb repair |
| 40 lb bag concrete | $2.50–$5 per bag | Tiny repairs, stepping stones |
How to estimate concrete slab cost
Concrete cost depends on volume, the amount ordered for waste, purchase method, local pricing, delivery minimums, and jobsite access. Bagged concrete often makes sense for small repairs and post holes; ready-mix is usually more practical for slabs, patios, garages, and driveways.
Start with base volume: length × width × thickness in feet. Divide cubic feet by 27 to get cubic yards. Apply the chosen waste percentage, round bag counts up to whole bags, then multiply the suggested order quantity by the correct unit price.
Ready-mix vs. bagged concrete
| Decision factor | Bagged concrete | Ready-mix |
|---|---|---|
| Typical project size | Small repairs and holes | Slabs and larger pours |
| Price input | Price per bag | Price per cubic yard |
| Extra costs | Mixer rental and labor | Delivery, short-load, pump, standby |
| Planning concern | Whole-bag rounding | Supplier minimum order |
Common concrete costs by project size
Assumes ready-mix at $150 per cubic yard. Bag prices vary by brand and store.
| Project | Volume | Ready-mix material cost |
|---|---|---|
| 10 × 10 ft patio at 4 in | 1.23 cu yd | ~$185 |
| 12 × 12 ft slab at 4 in | 1.78 cu yd | ~$267 |
| 20 × 20 ft garage at 4 in | 4.94 cu yd | ~$741 |
| 24 × 24 ft driveway at 5 in | 8.89 cu yd | ~$1,333 |
Related calculators
Concrete slab calculator · Concrete driveway calculator · Post hole concrete calculator · All concrete shapes
FAQ
How much does concrete cost per cubic yard?
In the US, ready-mix concrete typically costs $125 to $195 per cubic yard delivered, with short-load fees for orders under 7 cubic yards. Prices vary by region, mix design, and delivery distance.
Is it cheaper to use bagged concrete or ready-mix?
Bagged concrete is usually cheaper for small jobs under 1 cubic yard. Ready-mix becomes more economical for larger slabs, driveways, and footings because bulk pricing and labor savings offset delivery costs.
How much does a 20×20 concrete slab cost?
A 20 by 20 ft slab at 4 inches is about 4.94 cubic yards. At $150 per cubic yard, material cost is roughly $740 before waste, reinforcement, and labor.