Common slab sizes
e.g. 20
e.g. 20
Concrete Slab Cost Estimate
Cost Breakdown
Estimated Total Cost
$2,646 - $4,892
20x20 ft, 4" slab ($7-$12/sf installed)
12,800+ estimates calculated this month
How Much Does a Concrete Slab Cost?
Last updated: 2026-05-28
A concrete slab costs $6-$13 per square foot installed for a typical residential project. That price covers the ready-mix concrete at $130-$190 per cubic yard, a compacted gravel base, wire mesh or rebar, and the labor to form, pour, and finish the slab. A plain 4-inch broom finish is cheapest. Thicker pours, a rebar grid, and decorative finishes push the cost up. I have poured slabs in the PNW where the subgrade was so wet we had to over-excavate and bring in extra gravel, and that site work cost more than the concrete itself. Always walk the site before you quote a slab.
Concrete Slab Cost by Size and Thickness
All prices are installed (concrete, gravel base, reinforcement, and labor). Removal, pumping, and decorative finishes are extra. These are 2026 national averages and vary by region.
| Slab Size | Area | 4 inch | 6 inch |
|---|---|---|---|
| 10x10 (shed pad) | 100 sq ft | $700-$1,300 | $850-$1,600 |
| 12x16 (patio) | 192 sq ft | $1,400-$2,800 | $1,650-$3,300 |
| 20x20 (garage) | 400 sq ft | $2,600-$4,900 | $3,100-$5,900 |
| 24x24 (2-car garage) | 576 sq ft | $3,700-$7,000 | $4,500-$8,400 |
| 24x40 (shop floor) | 960 sq ft | $6,200-$11,800 | $7,500-$14,500 |
Highlighted row = most common small project. Add $2-$6/sf to remove an existing slab first.
What Each Part of a Slab Costs
Breaking the slab into line items shows where the money goes and where you can adjust the bid.
| Line Item | Typical Cost | Notes |
|---|---|---|
| Ready-mix concrete | $130-$190/cu yd | Delivered, 3,000-4,000 PSI |
| Gravel base | $1.50-$3/sf | Compacted, not optional on bare soil |
| Wire mesh | $0.35-$0.65/sf | Light reinforcement for patios |
| Rebar grid | $0.80-$1.50/sf | Load-bearing slabs, driveways |
| Place and finish labor | $3-$16/sf | Broom cheapest, stamped priciest |
| Old slab removal | $2-$6/sf | Plus dump fee, varies by thickness |
A short-load fee of $50-$150 applies to any ready-mix pour under 3 cubic yards.
Concrete Slab Cost & Installation Guide
Pricing by size and thickness, what each line item costs, how to calculate cubic yards, and what to know before you pour.
How Much Does a Concrete Slab Cost in 2026?
A concrete slab costs $6-$13 per square foot installed for most residential projects. That covers the ready-mix concrete, the gravel base, reinforcement, and the labor to form, pour, and finish it. A plain 4-inch slab sits at the low end. Thicker pours, rebar, and decorative finishes push the high end.
- 10x10 shed pad (4 inch): $700-$1,300 installed
- 12x16 patio (4 inch): $1,400-$2,800 installed
- 20x20 garage slab (5 inch): $2,900-$5,400 installed
- 24x40 shop floor (6 inch): $7,500-$14,500 installed
The ready-mix concrete itself runs $130-$190 per cubic yard delivered as of 2026, and a short-load fee of $50-$150 often applies on pours under 3 yards. Prices vary by region, so verify local rates before you bid.
Key Takeaways
- Standard installed range: $6-$13 per sq ft
- Ready-mix concrete: $130-$190 per cubic yard delivered
- Short-load fee of $50-$150 on small pours under 3 yards
What Drives Concrete Slab Cost Up or Down?
Thickness, finish, and reinforcement are the three biggest cost drivers, but site work can swing a bid more than any of them.
- Thickness: A 6-inch slab uses 50% more concrete than a 4-inch slab of the same size. Step up thickness for driveways, shops, and anything that carries vehicles.
- Finish: A broom finish adds $3-$6/sf in labor. Stamped or decorative work jumps to $9-$16/sf.
- Reinforcement: Wire mesh runs about $0.35-$0.65/sf. A rebar grid runs $0.80-$1.50/sf and is worth it on anything load-bearing.
- Gravel base: A compacted gravel base adds $1.50-$3/sf and is not optional on bare soil. Skipping it is the fastest way to crack a slab.
- Demolition: Removing and hauling an old slab adds $2-$6/sf depending on thickness and access.
- Access and pumping: If the truck cannot reach the pour, a concrete pump adds $800-$1,500 to the day.
Key Takeaways
- A 6-inch slab uses 50% more concrete than a 4-inch slab
- Gravel base ($1.50-$3/sf) is not optional on bare soil
- A concrete pump adds $800-$1,500 when the truck cannot reach
How Much Concrete Do You Need for a Slab?
Concrete is ordered in cubic yards. To find yards, multiply length by width by thickness in feet, then divide by 27. Add 10% for waste, spillage, and uneven subgrade.
- Formula: (length ft x width ft x thickness ft) / 27 = cubic yards
- 4-inch slab: a 20x20 area needs about 5.4 cubic yards with waste
- 6-inch slab: the same 20x20 area needs about 8.1 cubic yards with waste
I always order to the next quarter yard and tell the driver I would rather send a little back than come up short and cold-joint the pour. For exact takeoffs, run the numbers through our concrete tools before you call the plant.
Key Takeaways
- Cubic yards = (L x W x thickness in feet) / 27
- Add 10% for waste and uneven subgrade
- Order to the next quarter yard to avoid coming up short
Concrete Slab Labor Cost: What Contractors Charge
Labor to place and finish a slab runs $3-$16 per square foot depending on the finish. Most concrete crews bid the slab as a unit price, not by the hour.
- Broom finish: $3-$6/sf (standard, slip-resistant, most common)
- Smooth steel-trowel: $4-$7/sf (interior floors, garages)
- Integral color: $6-$10/sf (color mixed into the concrete)
- Exposed aggregate: $7-$12/sf (decorative, hides wear)
- Stamped: $9-$16/sf (patterns and texture, slowest to install)
A three-person crew pours and finishes a 400 sq ft slab in a single day once the forms and base are ready. The prep, the forming, and the gravel work usually take longer than the pour itself.
Key Takeaways
- Place and finish labor: $3-$16/sf by finish type
- Broom finish is the standard at $3-$6/sf
- Forming and base prep take longer than the pour
Common Concrete Slab Cost Mistakes
Skipping the base and underestimating site prep are the two mistakes I see wreck slab budgets. A slab is only as good as what sits under it.
- Pouring on dirt. A slab without a compacted gravel base will crack and settle. The base is $1.50-$3/sf and it is the cheapest insurance on the job.
- Forgetting control joints. Concrete cracks. Control joints decide where. Cutting them within 24 hours keeps random cracks out of the finished surface.
- Underbidding small pours. A short-load fee of $50-$150 hits any pour under 3 yards. On a small pad that fee can be 20% of the concrete cost.
- Ignoring access. If the mixer cannot back up to the forms, you are renting a pump or wheelbarrowing yards by hand. Walk the site before you quote.
- Not budgeting for removal. Tearing out an old slab adds $2-$6/sf and a dump fee. Homeowners almost never account for it.
Key Takeaways
- A compacted gravel base prevents cracking and settling
- Cut control joints within 24 hours to control cracking
- Short-load fees ($50-$150) hit any pour under 3 yards
Common Slab Mistakes That Cost Money
- Pouring on dirt instead of a gravel base. A slab without a compacted base will crack and settle. The base is $1.50-$3/sf and it is the cheapest insurance on the job. I have torn out year-old slabs that were poured straight on wet PNW soil.
- Forgetting control joints. Concrete cracks, period. Control joints decide where it cracks. Cut them within 24 hours of the pour and you keep random cracks out of the finished surface.
- Underbidding small pours. A short-load fee of $50-$150 hits any pour under 3 yards. On a small shed pad that fee can be 20% of your concrete cost. Build it into the bid.
- Not checking truck access. If the mixer cannot back up to the forms, you are renting a pump for $800-$1,500 or wheelbarrowing yards by hand. Walk the site before you quote.
- Skipping rebar on load-bearing slabs. Wire mesh is fine for a patio. A driveway or shop floor carrying vehicles needs a rebar grid. The upgrade is under $1/sf and it prevents the slab from failing under load.
Related Tools
- Concrete Calculator - Calculate cubic yards and bags needed for slabs, footings, and columns.
- Concrete Cost Per Yard - Check current ready-mix pricing per cubic yard delivered.
- Cubic Yard Calculator - Convert any volume to cubic yards for ordering bulk material.
- Rebar Weight Calculator - Estimate rebar weight and cost for slab reinforcement.
- Gravel Calculator - Figure out how much gravel you need for the slab base.
- Contractor Markup Calculator - Make sure your slab bids include the right markup for overhead and profit.
How to Use This Calculator
Enter Your Slab Dimensions
Input the length and width of the slab in feet, or tap a common size preset. The calculator works for any rectangular slab from a small shed pad to a full shop floor.
Choose the Thickness
Pick 4 inches for patios and walkways, 5 inches for garages, or 6 inches for driveways and shops. Thickness drives how many cubic yards of concrete you need.
Select Finish and Reinforcement
Choose a broom, smooth, colored, exposed aggregate, or stamped finish, then add wire mesh or a rebar grid. Each option adjusts the labor and material cost per square foot.
Add Base and Removal
Include a compacted gravel base if you are pouring on bare soil, and check old slab removal if you are tearing out existing concrete first. Enter your state for regional pricing.
Concrete Slab Cost Formulas
Area = Length x Width
Concrete (cu yd) = Area x (Thickness / 12) / 27 x 1.10
Concrete Cost = Cubic Yards x $130-$190/yd
Labor = Area x finish rate ($3-$16/sf)
Base = Area x $1.50-$3/sf (if gravel base)
Reinforcement = Area x mesh/rebar rate
Removal = Area x $2-$6/sf (if removing old slab)
Total = Concrete + Labor + Base + Reinforcement + RemovalWhere:
- Thickness
- = 4 in (patios), 5 in (garages), 6 in (driveways and shops)
- Finish
- = Broom $3-$6/sf, smooth $4-$7/sf, colored $6-$10/sf, exposed $7-$12/sf, stamped $9-$16/sf
- Reinforcement
- = Wire mesh $0.35-$0.65/sf, rebar grid $0.80-$1.50/sf
- Waste
- = 10% added to concrete volume for spillage and uneven subgrade
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Frequently Asked Questions
How much does a concrete slab cost per square foot?
A concrete slab costs $6-$13 per square foot installed in 2026, including the ready-mix concrete, gravel base, reinforcement, and the labor to form, pour, and finish it. A plain 4-inch broom-finished slab sits at the low end. A 6-inch slab with rebar and a stamped finish runs toward the high end. The concrete alone is $130-$190 per cubic yard delivered.
How much does a 20x20 concrete slab cost?
A 20x20 concrete slab (400 sq ft) costs $2,400-$5,400 installed depending on thickness and finish. A 4-inch broom-finished pad with a gravel base and wire mesh runs about $2,600-$4,900. Step up to a 5-inch slab for a garage and you add roughly 25% to the concrete. That size needs about 5.4 cubic yards of concrete at 4 inches thick.
Is a gravel base really necessary under a slab?
Yes. A compacted gravel base is the single most important thing under a slab. It costs $1.50-$3 per square foot and it gives the concrete a stable, draining surface that resists cracking and settling. I have torn out slabs poured straight on dirt that cracked within a year. The base is the cheapest insurance on the whole job. Skip it and you pay for it twice.
How do contractors price a concrete slab for a client?
Most concrete contractors price a slab as a unit price per square foot, then break it into line items: concrete, gravel base, reinforcement, forming, and finishing. They calculate the cubic yards with our concrete calculator, add 10% for waste, mark up materials 15-30%, and add a short-load fee on small pours. A clean bid lists each item so the homeowner can see exactly what drives the price. Try EstimationPro free to build a full slab bid with line items in minutes.
How thick should a concrete slab be?
Four inches is standard for patios, sheds, and walkways. Go to five inches for a garage that holds a car, and six inches for driveways, shops, or anything carrying heavy vehicles. A 6-inch slab uses 50% more concrete than a 4-inch slab of the same size, so thickness has a real cost impact. For load-bearing slabs, always add a rebar grid instead of wire mesh.
How much concrete do I need for a slab?
Multiply length by width by thickness in feet, then divide by 27 to get cubic yards. Add 10% for waste. A 20x20 slab at 4 inches needs about 5.4 cubic yards. The same slab at 6 inches needs about 8.1 cubic yards. Run an exact takeoff with our concrete volume calculator before you call the ready-mix plant.
Does the price include removing an old slab?
No, removal is extra. Tearing out and hauling an old slab adds $2-$6 per square foot plus a dump fee, depending on thickness and access. A 4-inch slab is faster to break out than a 6-inch reinforced one. Homeowners almost never budget for demolition, so it is worth calling out as its own line item on the estimate.
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