20×24 Concrete Slab (4 inches): Yards, Feet & Bags
A 20×24 slab at 4 inches is a common size for driveway section or shop floor. It’s usually manageable with bags, but if access is easy you may prefer ready-mix for speed and consistency.
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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 delivery access for the truck.
Neglecting proper base preparation can lead to cracking; make sure to compact the subgrade and use forms that support thickened edges.
Apply a smooth finish and keep the surface moist during curing to achieve optimal strength.
How to Estimate This Slab in 3 Steps
Measure
Length 20 ft, width 24 ft, thickness 4 in.
Compute Volume
Area: 480 sq ft → volume: 160.0 ft³ → 5.93 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?
Consider your project size, access for delivery, and whether you can mix on-site.
How do I account for waste in my concrete project?
Always add extra to your estimate to cover potential spills or miscalculations.
What is the best way to prepare the base for my slab?
Excavate to a stable layer, compact the soil, and ensure proper drainage for the best results.
How thick should my concrete slab be for a driveway?
A thickness of at least four inches is generally recommended for durability under vehicle loads.
Related Slab Sizes
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