Concrete Calculator
Calculate cubic yards of concrete needed for slabs, footings, and patios
Shape
Patios, floors, pads, square footings
Enter your dimensions above to see results
Tips & Notes
- •Standard residential slabs and patios use 4" thickness.
- •Driveways and areas with vehicle traffic need 6" minimum.
- •Order 10% extra to account for waste and spillage.
- •One 60 lb bag yields 0.45 cu ft. One 80 lb bag yields 0.60 cu ft.
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Pro tips for concrete
- ›Standard residential slabs and patios use 4" thickness.
- ›Driveways and areas with vehicle traffic need 6" minimum.
- ›Order 10% extra to account for waste and spillage.
- ›One 60 lb bag yields 0.45 cu ft. One 80 lb bag yields 0.60 cu ft.
Frequently asked questions
How much concrete do I need for a 10×10 slab?▾
A 10×10 slab at 4" thick is 100 sq ft × 0.33 ft = 33 cubic feet = 1.23 cubic yards. Order 1.35 yards to allow ~10% waste. Most ready-mix plants have a 1-yard minimum and charge short-load fees under 3 yards.
How many 60 lb or 80 lb bags do I need per cubic yard?▾
One cubic yard = 27 cubic feet. A 60 lb bag yields 0.45 cu ft (60 bags/yard). An 80 lb bag yields 0.60 cu ft (45 bags/yard). For anything over 0.5 cubic yards, ready-mix delivery is usually cheaper and faster than bagged.
How thick should my concrete slab be?▾
Residential patios and walkways: 4". Driveways: 5"–6". Garage floors: 4"–6". Footings vary by code and soil. Always include #4 rebar on 18"–24" grid or wire mesh for slabs over 50 sq ft to prevent cracking.
How much does concrete cost in 2026?▾
Ready-mix concrete runs $125–$175/cubic yard delivered (plus $50–$150 short-load fees under 3 yards). Bagged concrete runs $4–$7 per 80 lb bag. Installed concrete (with forms, labor, finishing): $6–$12/sq ft for plain, $10–$20/sq ft for stamped or stained.
How much extra concrete should I order?▾
Always order 10% more than your calculated volume. Footings, uneven excavation, and over-pour at form edges easily eat 5–8%. Running out mid-pour means a cold joint and a much weaker slab — order generously.