50x50 Concrete Slab, 4 Inches Thick
Poured 4 in thick, a 50 × 50 ft slab covering 2,500 sq ft needs about 33.95 cubic yards of concrete once 10% is added for waste. For ready-mix, order 34 cu yd for the 50x50, about $4,760 – $6,120 delivered. Bagged, the same 50x50 is 1,528 80 lb or 2,038 60 lb bags, about $10,190 – $14,266 for the concrete alone.
- Ready-mix order
- 34 cu yd
- Ready-mix cost
- $4,760 – $6,120
- 80 lb bags
- 1,528
- Bag cost
- $10,190 – $14,266
The 50x50 (4 in) prices are national material ranges as of 2026-09, not a quote from a supplier.
Pouring a 50x50 slab
A 50x50 slab, 2,500 sq ft, is a large square shop or ag building: room for a tractor, implements, vehicles and a workshop corner with space to turn around.
This is a contractor job, usually poured in strips or sections with a pump, because no crew can finish 2,500 sq ft by hand before the concrete stiffens.
At 4 in thick, the joint grid runs about every 10 ft, so the floor ends up as about 25 panels.
A 4 in 50x50 pour: check first
- Ask for the pour plan: number of trucks, the pump, and where the construction joints go.
- For a loader tractor or farm trucks, consider 6 in with rebar.
- Plan drains for washing equipment, and slope toward them.
Full plan for a 50x50 slab, 4 in
- Area
- 2,500 sq ft
- Thickness
- 4 in
- Volume
- 33.95 cu yd
Bagged concrete estimate (DIY)
$12,611 – $18,208
Est. as of 2026-09 — not a live quote
Ready-mix delivered (materials only)
$4,760 – $6,120
Est. as of 2026-09 — not a live quote
For a pour this size, ready-mix delivery is typically more practical than mixing bags by hand.
Shopping list
- Concrete mix (60 lb bags) Or 3,056 × 40 lb, 2,445 × 50 lb or 1,528 × 80 lb bags. 2,038 bags
- Ready-mix concrete Alternative to bagged mix; most suppliers have a 1 cu yd order minimum. 34 cu yd
- Compactable gravel sub-base 4 in compacted base beneath the slab. 41.67 tons
- 6x6 welded wire mesh Reinforcement for crack control; not a substitute for engineered rebar on structural slabs. 2,750 sq ft
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Buy bagged concrete
Pick up bagged mix and reinforcement from a hardware store for smaller pours.
View shopping listAssumptions
- Waste allowance: 10% applied to account for over-excavation and spillage.
- Approx. wet weight: 137,500 lb (68.8 tons).
- Prices are national-average retail/delivery ranges as of 2026-09, not live quotes.
Bags or ready-mix for a 50x50 slab, 4 in?
The 50x50 at 4 in needs 5 trucks: 34 cu yd at 8 cu yd a load, the low end of what a truck carries, for about $4,760 – $6,120. Ask the supplier to space the trucks so each load goes down before the last one stiffens (a wet edge), line up enough hands to place and finish 2,500 sq ft at 4 in, and ask about a pump if the truck can't reach every corner of the 50x50. Ready-mix wins for this 50x50 by roughly $6,788 (range midpoints), and nobody has to mix 1,528 bags by hand.
Is 4 in thick enough for a 50x50 slab?
For a 50x50 garage or shop floor that carries passenger cars, 4 in is common and above the IRC minimum of 3-1/2 in. Go to 5 or 6 in if the 50x50 will hold heavy pickups, an RV, a car lift or a tractor, or sits on soft or clay soil, and check your local code first. At 6 in the same 50x50 takes about 50.93 cu yd.
Control joints for a 50x50 slab at 4 in
A 50x50 slab at 4 in shrinks as it cures, and without joints it cracks wherever it chooses. The usual rule (ACI and PCA guidance) puts joints in a 50x50 at 4 in every 8 to 12 ft, 24 to 36 times the thickness, cut 1 in deep (a quarter of the thickness) as soon as the surface takes the saw without raveling, usually within the first day.
On the 50x50 at 4 in, a joint every 10 ft or less means 4 joints each way: 25 panels of about 10 × 10 ft and 400 ft of saw cut.
How much a 50x50 slab 4 in thick weighs
At roughly 150 lb per cubic foot of wet concrete, a 50x50 at 4 in puts about 137,500 lb (68.8 tons) on the ground. As bags, the 50x50 is 1,528 80 lb bags, 122,240 lb in all: about 82 trips in a pickup carrying 1,500 lb a load. Nobody hauls 122,240 lb of bags for a 50x50 in a pickup; it comes by ready-mix truck or as pallets on a delivery truck.
The 50x50 at 4 in against nearby sizes
Every row uses the same 10% waste and prices as the 50x50 at 4 in; costs are for the concrete only.
| Slab | Cu yd | 60 lb bags | 80 lb bags | Ready-mix order | Bags cost | Ready-mix cost |
|---|---|---|---|---|---|---|
| 40x60 slab, 4 in | 32.59 | 1,956 | 1,467 | 32.75 cu yd | $9,780 – $13,692 | $4,585 – $5,895 |
| 50x50 slab, 4 in (this page) | 33.95 | 2,038 | 1,528 | 34 cu yd | $10,190 – $14,266 | $4,760 – $6,120 |
Questions about a 50x50 slab, 4 in
How many bags of concrete for a 50x50 slab 4 inches thick?
A 50x50 slab at 4 in takes about 1,528 80 lb bags or 2,038 60 lb bags (or 2,445 50 lb, 3,056 40 lb), with 10% added for waste: 916.7 cubic feet in all.
How many yards of concrete for a 50x50 slab 4 inches thick?
33.95 cubic yards with waste (30.86 without) for a 50x50 at 4 in. Round the 50x50 order to 34 cu yd: plants batch in quarter yards and most won't send less than a yard.
How much does a 50x50 concrete slab 4 inches thick cost?
Concrete alone for the 50x50 runs about $4,760 – $6,120 for 34 cu yd of ready-mix delivered, or $10,190 – $14,266 for 2,038 60 lb bags. Add a 4 in gravel base and wire mesh and the bagged 50x50 plan comes to $12,611 – $18,208. Labor, forms and finishing for a 50x50 at 4 in come on top of these national ranges (as of 2026-09), which are not quotes.
How much does a 50x50 concrete slab 4 inches thick weigh?
About 137,500 lb (68.8 tons) of wet concrete for the 50x50, at 150 lb per cubic foot. The 1,528 80 lb bags for a 50x50 weigh 122,240 lb: about 82 trips in a pickup carrying 1,500 lb a load.
Where do control joints go on a 50x50 slab 4 inches thick?
On a 50x50 at 4 in, every 8 to 12 ft (24 to 36 times the thickness), sawn 1 in deep. On the 50x50 at 4 in, a joint every 10 ft or less means 4 joints each way: 25 panels of about 10 × 10 ft and 400 ft of saw cut.
Limitations
The 50x50 figures at 4 in are material estimates and typical price ranges, not a quote or a structural design. Confirm that 4 in, the reinforcement and the joint layout suit your soil, loads and local code for a 50x50 slab with a qualified professional.