24×36 Concrete Slab (6 inches): Yards, Feet & Bags
This 24 ft x 36 ft concrete slab, at 6 inches thick, is perfect for a driveway section or a shop floor. Consider whether to use bags or ready-mix based on site 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)
Check yield on the label and round to 0.25 yd³ for accurate ordering based on your project's needs.
Ensure your base is well-compacted and forms are secure to prevent shifting during pouring.
Smooth the surface for a clean finish and keep it moist for a general curing process.
Choosing the Right Slab Thickness for 24×36
For a driveway section, a 6-inch slab fits many heavy load jobs, but subgrade quality, reinforcement, and local requirements still matter.
Current spec
This page estimates a 24×36 slab poured at 6 inches.
Load check
Best fit depends on whether this is mainly pedestrian use, storage, or heavier wheel traffic.
Upgrade trigger
If you expect heavier loads later, compare this design against the alternate thickness before ordering.
driveway section Base Work for a 6-inch Slab
Most slab problems start below the concrete. Keep the base level, compacted, and consistent before you pour.
- Strip loose topsoil and organic material until you reach firm subgrade.
- Compact the base in lifts so the 24×36 slab does not settle unevenly.
- Check form height and diagonal measurements before concrete arrives.
- Plan reinforcement, joints, and edge support based on the intended driveway section use.
Worked Example for 24×36 at 6 Inches
Step-by-step calculation for this exact slab:
- Convert thickness to feet: 6 ÷ 12 = 0.5000 ft
- Compute area: 24 × 36 = 864 sq ft
- Volume in cubic feet: 864 × 0.5000 = 432.00 ft³
- Convert to cubic yards: 432.00 ÷ 27 = 16.000 yd³
- Add 10% waste buffer: 16.000 × 1.10 = 17.600 yd³
How to Order Concrete for 24×36
This slab needs about 16.00 yd³ of concrete, or 720 80 lb bags before waste. With a waste cushion, plan around 17.60 yd³.
For this volume, ready-mix is usually the safer plan. Round up, confirm delivery minimums, and make sure your crew can place and finish the slab without delays.
Adjust dimensions in the slab calculator or compare bag counts here.
Bag Counts by Waste Buffer for 24×36
Pick a buffer based on site conditions: smooth forms and good subgrade can run leaner; uneven excavation or hard-to-reach pours need more cushion.
| Buffer | Yards (yd³) | 80 lb bags | 60 lb bags | 40 lb bags |
|---|---|---|---|---|
| +5% tight pour | 16.80 | 757 | 1008 | 1513 |
| +10% typical | 17.60 | 793 | 1056 | 1585 |
| +15% rough subgrade | 18.40 | 828 | 1104 | 1656 |
6-inch Slab Curing Stages
For a driveway section, cure time matters more because wheel loads and concentrated weight can punish green concrete too early.
First 24 hours
Protect edges, prevent washout, and avoid unnecessary traffic while the slab sets.
Days 2-7
Maintain curing conditions and monitor joints, surface drying, and weather exposure.
Up to 28 days
Concrete keeps gaining strength, so wait for the right service window before heavy use.
How to Estimate This Slab in 3 Steps
Measure
Length 24 ft, width 36 ft, thickness 6 in.
Compute Volume
Area: 864 sq ft → volume: 432.0 ft³ → 16.00 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 bagged concrete and ready-mix?
Consider the size of your project and accessibility; bagged is great for smaller areas, while ready-mix can save time on larger pours.
How do I determine the right thickness for my slab?
Thickness depends on the intended use; heavier loads require more thickness for stability and durability.
What base preparation is necessary for a concrete slab?
Ensure the ground is compacted and level; a well-graded base helps prevent settling and cracking.
How can I minimize waste during my concrete project?
Estimate your needs carefully and order a little extra to cover any mistakes or spillage.
Related Slab Sizes
Ready to Calculate Your Project?
Get instant estimates for cubic yards, cubic feet, and bag counts. No signup required.