Concrete Slab Cost Per Square Foot Worksheet
A slab budget starts with approved length, width and thickness, then adds base preparation, reinforcement, concrete delivery, placing and finish. The tables show how area and volume affect arithmetic using replaceable assumptions; they are not observed pricing data.
Key takeaways
- Area supports quote comparison, while concrete supply is normally quantified by volume.
- A 6-inch slab uses 50% more concrete volume than a 4-inch slab with the same footprint.
- Thickness, base and reinforcement must come from project requirements, not the cost worksheet.
- Compare bids that state excavation, base, concrete, reinforcement, finish, access and delivery terms.
- The $6 to $12 range is an illustrative input to replace with a current local quote.
Concrete slab cost per square foot: the range
For an illustrative worksheet only, assume $6 to $12 per square foot and use $8 as an arithmetic midpoint. Replace those inputs with a current local quote for a stated thickness, finish and scope.
Enter approved length, width and thickness in the concrete slab calculator for quantities, then apply a current quoted rate.
Cost per square foot by slab thickness
Thickness is the biggest driver of price per square foot, since a thicker slab uses proportionally more concrete for the same footprint. A 6 inch slab uses about 50% more concrete by volume than a 4 inch slab over the same area.
| Thickness | Typical use | Assumed input per sq ft |
|---|---|---|
| 4 inches | Patios, walkways, sheds | $8 to $10 |
| 5 to 6 inches | Driveways, garage floors | $10 to $12 |
| 6+ inches, commercial | Heavy-load or commercial slabs | $10 to $18 |
For a deeper look at how much thickness a specific project needs, see how thick a concrete slab should be before pricing the job.
What is included in the price per square foot
Request materials, labor, site preparation, equipment and delivery as visible scope items. This page has no dataset for a nationwide cost split.
| Cost item | Assumed input per sq ft | Scope to confirm |
|---|---|---|
| Ready-mix concrete | $3 to $7 | Mix, quantity and delivery |
| Labor to form, pour, finish | $3 to $5 | Forms, placing and finish |
| Site prep and grading | $1 to $3 | Excavation, base and access |
| Equipment and delivery | Quoted separately | Equipment, travel and minimums |
How region changes the price per square foot
State the slab area, thickness, base, reinforcement, finish, access and delivery in each quote.
Apply current rates only to the slab area, thickness, base, reinforcement, finish, access and delivery.
Reinforcement and finish: what pushes the price up
ASTM A615 defines reinforcing-bar material requirements but does not select a bar size or establish whether a slab needs rebar. Price only the reinforcement, supports, laps and placement shown in the approved project details.
A driveway may have different traffic, base, drainage, joint, finish and reinforcement requirements from a patio. The concrete driveway cost worksheet lists that scope without prescribing a slab design.
Getting an exact price for your slab
Per square foot averages are useful for budgeting, but the only way to get an exact number is to work from your actual dimensions and thickness. Volume, not area, is what a concrete supplier actually charges for.
For a slab specifically, plugging your length, width and thickness into the slab calculator returns cubic yards, the number of 60 and 80 lb bags if you are pouring by hand, and an estimated material cost, so you can compare it against any contractor bid before you sign.
Frequently asked questions
What is the average cost per square foot for a concrete slab?
How much does a 4 inch concrete slab cost per square foot?
How much does a 6 inch concrete slab cost per square foot?
Is concrete priced per square foot or per cubic yard?
How much does concrete cost per square foot for a driveway?
Sources and references
These references and structured source records support the method and material data used on this page.
- American Concrete Institute (institutional site)
- ASTM A615: Standard Spec for Carbon-Steel Bars (rebar)
- NRMCA: Ready Mixed Concrete
- Concrete (Wikipedia)