An 800 sq ft concrete slab typically costs $6,400-$11,200 installed, with an average near $8,800 for a standard 4-inch slab. The final price depends on concrete thickness, reinforcement, grading, access, local labor rates, and whether the site needs excavation or old concrete removal.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Installed 800 sq ft slab | $6,400 | $8,800 | $11,200 | Standard 4-inch slab; ordinary access |
| Installed price per sq ft | $8 | $11 | $14 | Labor and basic materials included |
| Concrete volume | 8.5 yd³ | 10 yd³ | 11 yd³ | Includes typical placement waste |
| Site preparation | $800 | $1,800 | $3,500 | Varies with grading and soil conditions |
What an 800 Sq Ft Concrete Slab Usually Costs
A basic 4-inch slab on a prepared, level site commonly runs $6,400-$8,800, or about $8-$11 per sq ft. A reinforced slab, thicker edges, difficult delivery access, or substantial base preparation can raise the total to $9,600-$11,200 or more. These ranges assume a straightforward residential pour, standard ready-mix concrete, and no major demolition or engineered foundation work.
For budgeting, about $8,800 is a reasonable midpoint for a standard 800 sq ft installation. Regional labor and concrete prices can move a quote outside this range, and unusually complex foundations require project-specific engineering and bids.
How Concrete, Labor, and Base Work Shape the Quote
The slab itself is only part of the bill. Contractors may price forming, reinforcement, placement, finishing, and site preparation separately or combine them into a per-square-foot estimate. The table shows common cost bands for an 800 sq ft job; line items vary by contractor and market.
| Quote component | Low | Average | High | Typical scope |
|---|---|---|---|---|
| Concrete and delivery | $1,500 | $2,200 | $3,000 | About 8.5-11 yd³ delivered |
| Labor and finishing | $2,000 | $3,000 | $4,000 | Forms, pour, screed, finish |
| Reinforcement and forms | $500 | $900 | $1,400 | Mesh or rebar, stakes, form lumber |
| Base, grading, and equipment | $1,000 | $1,800 | $2,800 | Compacted aggregate and machinery |
| Permits and disposal | $0 | $400 | $1,000 | Local permits or limited haul-away |
Check what the per-square-foot quote includes before comparing contractors. A low rate may exclude base stone, reinforcement, pump rental, disposal, or permit fees.
Thickness, Reinforcement, and Soil Conditions That Raise Price
At 4 inches thick, an 800 sq ft slab requires roughly 9.9 cubic yards before waste; ordering about 10-11 yd³ is common. Increasing thickness to 6 inches raises concrete volume by 50%, often adding roughly $1,000-$2,500 to a residential quote after material and placement needs are considered.
Rebar, fiber, or wire mesh can add about $0.50-$2 per sq ft, depending on the design and material. Soft soil, slopes, drainage problems, or a required compacted base deeper than 4-6 inches can add $1,000-$4,000 or more. A garage slab with thickened edges or vehicle loads may need a design beyond a basic patio specification.
Confirm slab thickness, edge details, and reinforcement in writing. Local building requirements and intended use matter; a driveway, garage, shed floor, and outdoor patio should not automatically be priced as identical slabs.
Where 800 Sq Ft Slab Quotes Differ by Region
Prices in lower-cost rural markets may be about 10%-20% below a national midpoint when crew availability and delivery distances are favorable. Major metro areas and high-cost coastal markets can run 15%-30% above it because of labor, insurance, permitting, and transportation charges. These are broad comparisons, not guaranteed local adjustments.
Remote sites may also pay more even in a lower-cost state if the ready-mix plant is far away or truck access is restricted. Ask whether the concrete supplier charges travel, short-load, or waiting fees, and whether those charges are already included in the contractor’s estimate.
How Many Crew Hours Does an 800 Sq Ft Pour Need?
A straightforward slab may take a crew of three to five workers roughly 1-2 days for forming, placement, finishing, and cleanup, with curing continuing after the crew leaves. Labor commonly represents about $2.50-$5 per sq ft, or $2,000-$4,000 for 800 sq ft, depending on finish detail and site access.
Finishing time is sensitive to weather and delivery timing. A pump truck may add approximately $500-$1,200 when the concrete truck cannot reach the forms. The contractor should state whether equipment, travel, and any extra crew time are included.
Excavation, Old Slab Removal, and Delivery Add-Ons
Removing existing concrete often costs $2-$6 per sq ft, or $1,600-$4,800 for 800 sq ft, including breaking and hauling in many markets. Excavation and export of unsuitable soil can add around $5-$15 per sq ft in difficult conditions. A simple grading adjustment may be much less, while retaining walls or drainage work can change the project substantially.
Concrete pumping, limited truck access, and disposal fees should appear as clear line items. If the site requires a pump, ask whether the minimum charge applies even when the pour takes less than a full day. A site visit helps prevent an estimate from overlooking these costs.
Three Realistic Quotes for Different Slab Scopes
A basic patio on a level, accessible site might total about $6,800: 800 sq ft at $8.50 per sq ft, using a 4-inch slab and minimal preparation. A standard reinforced slab with a compacted base could reach $8,800: $11 per sq ft, including ordinary forming, labor, and finishing.
A garage slab with 6-inch thickness, reinforced edges, and moderate grading might cost about $12,400, or $15.50 per sq ft. That example assumes around 10-12 crew hours for placement and finishing, plus added concrete and base work; engineered specifications or major excavation could push the quote higher.
Which 800 Sq Ft Slab Choices Can Lower the Bill?
Keep the project footprint and slab specification matched to actual use. A decorative finish, unnecessary extra thickness, or extensive reinforcement can add cost without serving a clear structural purpose. Do not reduce thickness or reinforcement where vehicle loads, soil conditions, or code requirements call for more.
Compare at least three written, scope-matched bids. Confirm that each covers the same thickness, concrete strength, base depth, reinforcement, finish, disposal, and access equipment. Clearing vegetation and providing unobstructed truck access may reduce labor or equipment charges, while scheduling outside peak contractor demand can improve availability without compromising the required design.