Concrete Calculator › 40×50 slab

Concrete for a 40×50 Slab at 6 inches

A 40×50 slab (2,000 sq ft) at 6 inches needs about 37.04 cubic yards of concrete — roughly $5,556. See the full breakdown.

You need
37.04 cu yd
Estimated material cost $5,556
Area
2,000 sq ft
Volume
1000.0 cu ft
80-lb bags
1667
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Adjust for your project

You need
37.04 cu yd
Estimated material cost $5,556
Area
2,000 sq ft
Volume
1000.0 cu ft
80-lb bags
1667

Material shopping list

  • Order about 37.04 cubic yards of concrete.
  • Budget about $5,556 before delivery, taxes, and labor.
  • Add 5–10% waste for uneven subgrade, cuts, settling, or spillage.

Formula & assumptions

Area = length x width. Volume = area x depth / 12. Cubic yards = cubic feet / 27. Cost = quantity x local unit price.

  • Default depth: 4 inches
  • Default price: $150 per cuyd
  • 80-lb bags yield: 0.6 cu ft each

These assumptions make the estimate easy for search engines and AI answer tools to verify. Replace the default price with your supplier quote for a local estimate.

Common questions about a 40×50 slab

How many bags of concrete do I need for a 40×50 slab at 6 inches?
You need 1000.0 cubic feet: about 1667 80-lb bags, 2223 60-lb bags, or 3334 40-lb bags. At that count, ready-mix delivery is cheaper, faster, and gives a consistent mix — bags make sense only if truck access is impossible.
How much weight can a 6-inch concrete slab hold?
A 6-inch slab over compacted base with rebar handles pickups, trailers, and most residential equipment loads. Commercial vehicle traffic or heavy point loads call for engineered thickness and reinforcement.
Should I pour thicker than 6 inches?
At 6 inches this slab already covers residential vehicle duty. Extra thickness past 6 inches buys little for a home project — proper base compaction, edge thickening, and cure time matter more.
Do I need rebar or wire mesh?
For patios and walkways, fiber-reinforced mix or wire mesh controls cracking fine. For driveways and anything carrying vehicles, use #3 or #4 rebar on an 18–24 inch grid, set on chairs at mid-slab — mesh stomped to the bottom of the pour does nothing.

Based on $150 per cuyd national average. Enter your local price for an exact quote. Estimate only.