A 16 x 24 concrete slab covers 384 square feet and typically costs $3,000-$7,700 installed, with an average near $5,200. Price depends on slab thickness, site preparation, reinforcement, concrete delivery, labor rates, and whether the slab needs a finished surface or permit.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Installed slab | $3,000 | $5,200 | $7,700 | $7.80-$20 per sq ft |
| Concrete volume | $550 | $800 | $1,150 | About 4-6 cubic yards, delivered |
| Site preparation | $300 | $850 | $1,800 | Grading, compacted base, access |
| Reinforcement and forms | $350 | $750 | $1,400 | Mesh or rebar, lumber, stakes |
Assumptions: Typical U.S. pricing for a detached ground-level slab with ordinary access; major excavation and building foundations are excluded.
What a 384-square-foot slab usually costs
A basic 4-inch slab on a prepared, level site generally runs $3,000-$4,600, or about $7.80-$12 per square foot. A reinforced slab with a thicker edge, upgraded finish, or moderate grading commonly reaches $4,600-$7,700, equivalent to roughly $12-$20 per square foot. An average quote of about $5,200 assumes standard concrete, routine forming, and typical labor.
For a straightforward project, budgeting $4,000-$6,000 is a practical starting point. The low end usually assumes truck access, little or no excavation, and a basic broom finish. Steep slopes, difficult access, drainage work, or structural requirements can put a quote above the typical high range. Smaller pours may also have minimum delivery or crew charges that raise the per-square-foot rate.
How concrete, labor, forms, and base shape the quote
Contractors may combine several tasks into a single installed price, so itemized estimates help show what is included. The ranges below are typical allowances for a 384-square-foot slab, not guaranteed line items; local material and labor rates vary.
| Quote component | Typical range | Basis | What changes it |
|---|---|---|---|
| Concrete and delivery | $550-$1,150 | $140-$220 per cubic yard | Thickness, mix, short-load fees |
| Labor and placement | $1,200-$2,700 | $40-$85 per worker-hour | Crew size, access, finish |
| Base, grading, forms | $650-$1,800 | Project allowance | Soil, slope, base depth |
| Reinforcement and finishing | $350-$1,200 | Mesh or rebar, surface work | Bar spacing, finish choice |
| Permits and disposal | $0-$850 | Local fees and haul-away | Jurisdiction, demolition scope |
Labor and site work often account for as much of the bill as the concrete itself. Confirm whether the quote includes forming, base compaction, reinforcement, control joints, cleanup, and disposal of excavated soil.
How thickness and reinforcement change concrete volume
A 4-inch slab across 384 square feet uses about 4.7 cubic yards before waste. A 5-inch slab takes about 5.9 cubic yards, while a 6-inch slab takes about 7.1 cubic yards. Contractors may order extra for uneven ground, spillage, or a thickened perimeter, so the delivered quantity can be higher than the mathematical volume.
Moving from 4 inches to 6 inches can add roughly $500-$1,500 or more. The difference depends on concrete rates, edge design, and added reinforcement. A 4-inch slab may suit light-duty uses such as patios, while vehicle loads, equipment, or local building plans may call for a thicker slab or engineered details. Rebar, wire mesh, and thicker edges should match the intended load rather than being added without a design reason.
How many crew hours does a 16 x 24 pour take?
For a clear, prepared site, a crew of three to five may spend 10-18 labor hours on layout, forms, placing, finishing, and cleanup, often spread across one or two visits. Excavation and base installation can add another 8-20 worker-hours. Curing takes longer than the pour: foot traffic may be restricted for at least a day, and vehicles usually need several days or more, depending on conditions and contractor guidance.
Ask whether the labor allowance covers preparation as well as pour day. A low bid may include only forming and placing concrete, leaving grading, compaction, or demolition as separate charges. Rain, hot weather, limited truck access, and tight placement windows can also affect crew time and scheduling.
Three realistic quotes for different slab scopes
| Example | Scope and labor | Estimated total |
|---|---|---|
| Basic patio | 4-inch slab, level ground, mesh, broom finish; 12-16 labor hours | $3,200-$4,500 |
| Shed or workshop floor | 4-inch slab, compacted base, rebar, thicker edges; 18-26 labor hours | $4,800-$7,000 |
| Uneven site with removal | Existing surface removal, grading, 5-6-inch pour, disposal; 24-36 labor hours | $7,000-$10,500 |
Assumptions: Standard ready-mix delivery and ordinary local labor; permits, plumbing, and engineered foundations are excluded unless noted.
Compare scope before comparing totals. A $4,000 estimate for a basic patio is not equivalent to a $4,000 bid that includes excavation, haul-away, and a compacted gravel base.
Regional labor rates can shift the installed price
Quotes in high-cost coastal metros may run about 15%-30% above a national middle estimate, while many rural markets may be 5%-15% lower. These differences reflect labor, concrete availability, travel, and contractor demand; they are not fixed regional tariffs. Remote locations can still cost more if delivery distance or small-load fees are substantial.
Use local written bids rather than a national average as the final budget. For example, a typical $5,200 scope could approach $6,000-$6,800 in a costly metro, or fall near $4,400-$4,950 in a lower-cost area when site conditions and materials are comparable.
Which extras can push the slab above the base quote?
Removing an existing concrete pad often adds $2-$6 per square foot, or about $770-$2,300 for 384 square feet, including breaking and hauling in many markets. Excavation and grading can add $500-$2,000, while a gravel base may add $300-$900. A permit may cost $50-$500 or more, depending on local rules and whether the slab supports a structure.
Get add-ons priced separately before signing. Ask about minimum-load charges, delivery distance, soil disposal, drainage changes, thickened edges, control joints, and finish upgrades. Stamped or colored concrete can add several dollars per square foot, making it a significant expense across a 384-square-foot area.
Where scope choices can lower a 16 x 24 slab bill
Keeping the footprint at 384 square feet, choosing a standard broom finish, and scheduling on a flexible date can help control costs. Clearing vegetation and providing truck access may reduce labor, provided the contractor approves the preparation plan. Compare at least three itemized quotes with the same thickness, base depth, reinforcement, finish, and cleanup terms.
Do not save money by reducing thickness or reinforcement below the requirements for the intended load. Instead, ask whether unnecessary decorative finishes, extensive excavation, or duplicate site-preparation charges can be removed. Confirm curing instructions and warranty terms, and have the contractor specify who handles permits and any required inspections.