How Much Concrete for a 30x30 Slab?
Quick Answer
For a standard 4-inch thick 30x30 foot slab, you will need approximately 11.11 cubic yards of concrete. We recommend ordering 12.5 cubic yards to account for a 10% waste margin.
Detailed Explanation
A 30x30 slab is a large project, typically used for a two-car garage, a large workshop, or a substantial patio. Because of the size, accuracy in ordering is critical to avoid running short during the pour.
Step-by-Step Math Breakdown
1. Convert thickness to feet: 4 inches ÷ 12 = 0.333 feet
2. Calculate square footage: 30 ft × 30 ft = 900 sq ft
3. Calculate cubic feet: 900 sq ft × 0.333 ft = 300 cubic feet
4. Convert to cubic yards: 300 ÷ 27 = 11.11 cubic yards
2. Calculate square footage: 30 ft × 30 ft = 900 sq ft
3. Calculate cubic feet: 900 sq ft × 0.333 ft = 300 cubic feet
4. Convert to cubic yards: 300 ÷ 27 = 11.11 cubic yards
Materials Note
Standard concrete weighs about 150 lbs per cubic foot. A 30x30 slab at 4 inches thick will weigh approximately 45,000 lbs (22.5 tons). A standard concrete mixer truck holds about 10 cubic yards, so a 30x30 slab will require at least two truck deliveries.