Primary material
62 bags
80 lb concrete mix
Use the calculated bag count as your buying starting point, then verify yield and pallet limits with the store.
24 x 24 concrete slab
A 24 ft by 24 ft slab — a common two-car garage — is 576 square feet. At 4 inches it needs about 7.82 cubic yards; a 6 inch garage floor needs about 11.73 yd³ with 10% waste. Adjust thickness, waste, and price below.
24 x 24 x 6 in
11.73 yd³
garage floor
Area
576 sq ft
24 ft x 24 ft
Material cost (6 in)
$1,760
ready-mix, material only
24x24 by thickness
A two-car garage floor is usually 5 to 6 inches over a compacted base with reinforcement. Four inches is shown for patio-style use. All figures include the default 10% waste.
| Thickness | Cubic yards | 80 lb bags | 60 lb bags | Ready-mix material |
|---|---|---|---|---|
| 4 in | 7.82 yd³ | 352 | 470 | $1,173 |
| 5 in | 9.78 yd³ | 440 | 587 | $1,467 |
| 6 in | 11.73 yd³ | 528 | 704 | $1,760 |
Bag counts are shown for reference only — at this size the bag totals confirm it is a ready-mix pour.
Want installed cost?
The figures here are material only. For labor, base prep, forms, reinforcement, and finishing, the concrete cost calculator gives a full installed range.
Shopping list
Use the calculated quantities as a starting cart, then compare store availability, delivery fees, pallet limits, and local ready-mix minimums before buying.
Primary material
62 bags
80 lb concrete mix
Use the calculated bag count as your buying starting point, then verify yield and pallet limits with the store.
Large pours
Ready-mix quote check
For high bag counts, compare the bagged route against local ready-mix minimums, delivery, access, and unload time.
Optional base
Gravel base
Base depth is project-specific. Estimate it separately before adding bags or bulk gravel to the order.
Optional forms
Forms and stakes
Plan lumber, stakes, screws, release, and bracing around the perimeter and any step-downs or curves.
Store buttons open retailer search results for now. Confirm exact product yield, pickup, delivery, and pallet rules before ordering.
Formula shown
1. Area is fixed at 576 sq ft
24 ft x 24 ft = 576 sq ft
2. Volume in cubic feet
576 sq ft x (thickness in / 12)
3. Yards and waste
yd³ = ft³ / 27, then add the waste allowance and round up to the load
Garage slab details matter
A garage floor usually wants a thickened edge or footing at the perimeter, reinforcement, a vapor barrier, and a slight slope to the door. Estimate the slab field here and add the haunch and reinforcement separately.
Sources
Sources checked
Checked against
Bag yields checked against Quikrete and Sakrete product specs; price ranges against published concrete cost guides.
How we check our numbersLast updated: June 29, 2026
FAQ
Cubic yards, ready-mix loads, garage thickness, cost, and reinforcement for a 24 ft by 24 ft slab.
A 24 ft by 24 ft slab is 576 square feet. At 4 inches thick it needs about 7.82 cubic yards with the default 10% waste. A 6 inch garage slab needs about 11.73 yd³. Both are ready-mix orders.
About 7.82 cubic yards at 4 inches, 9.78 yd³ at 5 inches, and 11.73 yd³ at 6 inches, all including 10% waste. A 24x24 two-car garage floor is commonly poured at 5 to 6 inches.
A two-car garage floor is typically 5 to 6 inches of concrete over a compacted base, often with rebar or welded wire and thickened edges. Four inches is more of a patio or light-duty thickness. Follow local code and your engineer for vehicle and storage loads.
At 352-plus bags of 80 lb mix even at 4 inches, a 24x24 slab is firmly a ready-mix pour. Bags would mean hundreds of bags and an impossible mixing pace for a single, monolithic slab.
Material alone for a 6 inch 24x24 slab is roughly $1,760 in ready-mix at typical prices. Installed cost adds labor, base prep, forms, reinforcement, and finishing and varies by region — use the concrete cost calculator for a full installed range.