30×30 Concrete Slab (6 inches): Yards, Feet & Bags
A 30 ft x 30 ft concrete slab is perfect for a driveway section or a spacious shop floor. Decide between bags or ready-mix based on your access and waste factor.
Choose Your Calculator
Slab Calculator
Enter any custom length, width, and thickness to get cubic yards and bag counts.
Open Slab CalculatorBag Calculator
Choose 40/60/80 lb bag sizes and estimate counts for your exact volume.
Open Bag CalculatorWant other sizes? Browse all slab size pages
Quick Answer
Tip: Always confirm the yield printed on your bag label. Bag yield guide
Large pour: consider ready-mix delivery for speed and consistent results. Bag counts this high can take significant mixing time.
Project Notes (Unique)
Round to 0.25 yd³ when ordering and ensure you have adequate delivery access for the truck.
Neglecting to properly prepare the base and install forms can lead to uneven surfaces and cracking.
Aim for a smooth finish and allow the concrete to cure slowly in a shaded area to prevent cracking.
How to Estimate This Slab in 3 Steps
Measure
Length 30 ft, width 30 ft, thickness 6 in.
Compute Volume
Area: 900 sq ft → volume: 450.0 ft³ → 16.67 yd³.
Add Waste
Add a small buffer for spillage and uneven subgrade, then round up when ordering.
Planning Notes
Common uses: driveway section, shop floor, large patio.
For more context and conversions, see the Concrete Calculator hub.
Frequently Asked Questions
What should I consider when choosing between bags and ready-mix concrete?
Consider the size of your project and access for delivery; ready-mix may be more efficient for larger slabs.
How do I calculate the amount of concrete needed?
Measure the length, width, and thickness of your slab, then use those dimensions to estimate your needs while allowing for waste.
What is the best way to prepare the base for my concrete slab?
Clear the area of debris, level it, and compact the soil to create a solid foundation for your slab.
How thick should my concrete slab be for different uses?
A thickness of inches is generally suitable for heavy loads like vehicles, while lighter uses may require less.
Related Slab Sizes
Ready to Calculate Your Project?
Get instant estimates for cubic yards, cubic feet, and bag counts. No signup required.