24x24 Concrete Slab, 4 Inches Thick
A 24 × 24 ft slab (576 sq ft) at 4 in thick takes about 7.82 cubic yards of concrete, with 10% extra for waste. For ready-mix, order 8 cu yd for the 24x24, about $1,180 – $1,550 delivered, short-load fee included. Bagged, the same 24x24 is 352 80 lb or 470 60 lb bags, about $2,350 – $3,290 for the concrete alone.
- Ready-mix order
- 8 cu yd
- Ready-mix cost
- $1,180 – $1,550
- 80 lb bags
- 352
- Bag cost
- $2,350 – $3,290
The 24x24 (4 in) prices are national material ranges as of 2026-09, not a quote from a supplier.
The 24x24 two-car garage slab
Twenty-four feet square is the most popular two-car garage size: both cars fit with room to open doors, plus shelves or a bench along the back wall.
Most two-car garages use one 16 ft door or two 8 to 9 ft doors, and a 24 ft front wall leaves space for either layout.
At 576 sq ft and 4 in thick, the pour is a single ready-mix truck, which keeps the job to one day for a small crew.
A 4 in 24x24 pour: check first
- Pick one wide door or two single doors before forming, because the threshold and anchor-bolt layout differ.
- Ask about frost protection: attached garages usually need footings like the house.
- Slope toward the door or a floor drain, and keep the slope gentle enough for a creeper or a jack to stay put.
Full plan for a 24x24 slab, 4 in
- Area
- 576 sq ft
- Thickness
- 4 in
- Volume
- 7.82 cu yd
Bagged concrete estimate (DIY)
$2,908 – $4,198
Est. as of 2026-09 — not a live quote
Ready-mix delivered, incl. short-load fee (materials only)
$1,180 – $1,550
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 704 × 40 lb, 564 × 50 lb or 352 × 80 lb bags. 470 bags
- Ready-mix concrete Alternative to bagged mix; most suppliers have a 1 cu yd order minimum. 8 cu yd
- Compactable gravel sub-base 4 in compacted base beneath the slab. 9.6 tons
- 6x6 welded wire mesh Reinforcement for crack control; not a substitute for engineered rebar on structural slabs. 634 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: 31,680 lb (15.8 tons).
- Prices are national-average retail/delivery ranges as of 2026-09, not live quotes.
- Ready-mix orders under 10 cu yd usually carry a short-load fee; the ready-mix range includes a flat $60-$110. Some suppliers charge per yard instead, so ask for the full fee schedule.
Bags or ready-mix for a 24x24 slab, 4 in?
7.82 cu yd for the 24x24 fits on one ready-mix truck (they carry about 8 to 10 cu yd). In bags the 24x24 would be 352 80 lb bags weighing 28,160 lb, so ready-mix is the practical choice. Under 10 cu yd most suppliers add a short-load fee, and the $1,180 – $1,550 range for the 24x24 includes one. Ready-mix wins for this 24x24 by roughly $1,455 (range midpoints), and nobody has to mix 352 bags by hand.
Is 4 in thick enough for a 24x24 slab?
Many residential garage floors the size of this 24x24 are poured 4 in thick, which clears the IRC minimum of 3-1/2 in for cars and light trucks. Go to 5 or 6 in if the 24x24 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 24x24 takes about 11.73 cu yd.
Control joints for a 24x24 slab at 4 in
A 24x24 slab at 4 in shrinks as it cures, and without joints it cracks wherever it chooses. ACI and PCA guidance spaces joints 24 to 36 times the thickness, which for this 24x24 at 4 in is every 8 to 12 ft, sawn 1 in deep (a quarter of the slab) once the surface holds up to the blade, usually within a day.
On the 24x24 at 4 in, a joint every 10 ft or less means 2 joints each way: 9 panels of about 8 × 8 ft and 96 ft of saw cut.
How much a 24x24 slab 4 in thick weighs
Wet concrete weighs about 150 lb per cubic foot, so the 24x24 pour is about 31,680 lb (15.8 tons). As bags, the 24x24 is 352 80 lb bags, 28,160 lb in all: about 19 trips in a pickup carrying 1,500 lb a load. Nobody hauls 28,160 lb of bags for a 24x24 in a pickup; it comes by ready-mix truck or as pallets on a delivery truck.
The 24x24 at 4 in against nearby sizes
Every row uses the same 10% waste and prices as the 24x24 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 |
|---|---|---|---|---|---|---|
| 20x20 slab, 4 in | 5.43 | 326 | 245 | 5.5 cu yd | $1,630 – $2,282 | $830 – $1,100 |
| 24x24 slab, 4 in (this page) | 7.82 | 470 | 352 | 8 cu yd | $2,350 – $3,290 | $1,180 – $1,550 |
| 20x30 slab, 4 in | 8.15 | 489 | 367 | 8.25 cu yd | $2,445 – $3,423 | $1,215 – $1,595 |
Questions about a 24x24 slab, 4 in
How many bags of concrete for a 24x24 slab 4 inches thick?
Plan on 211.2 cubic feet for the 24x24, which is 352 80 lb bags, 470 60 lb bags, 564 50 lb or 704 40 lb bags once 10% waste is in.
How many yards of concrete for a 24x24 slab 4 inches thick?
7.82 cubic yards with waste (7.11 without) for a 24x24 at 4 in. Round the 24x24 order to 8 cu yd: plants batch in quarter yards and most won't send less than a yard.
How much does a 24x24 concrete slab 4 inches thick cost?
Concrete alone for the 24x24 runs about $1,180 – $1,550 for 8 cu yd of ready-mix delivered, short-load fee included, or $2,350 – $3,290 for 470 60 lb bags. Add a 4 in gravel base and wire mesh and the bagged 24x24 plan comes to $2,908 – $4,198. Labor, forms and finishing for a 24x24 at 4 in come on top of these national ranges (as of 2026-09), which are not quotes.
How much does a 24x24 concrete slab 4 inches thick weigh?
About 31,680 lb (15.8 tons) of wet concrete for the 24x24, at 150 lb per cubic foot. The 352 80 lb bags for a 24x24 weigh 28,160 lb: about 19 trips in a pickup carrying 1,500 lb a load.
Where do control joints go on a 24x24 slab 4 inches thick?
On a 24x24 at 4 in, every 8 to 12 ft (24 to 36 times the thickness), sawn 1 in deep. On the 24x24 at 4 in, a joint every 10 ft or less means 2 joints each way: 9 panels of about 8 × 8 ft and 96 ft of saw cut.
Limitations
The 24x24 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 24x24 slab with a qualified professional.