Concrete Slab Cost in 2026: Bags, Ready-Mix and Labor by Size

A 20x20 slab at 4 inches takes 5.43 cubic yards of concrete with waste, which is about $815 of ready-mix at a typical 2026 price of $150 a yard, or 245 bags of 80 lb mix at roughly $1,593. Hired out, a finished slab commonly runs $6 to $12 per square foot in 2026, so the same 20x20 lands between $2,400 and $4,800 with labor, base and reinforcement included.

Slab / FootingRound Column / Post

Length (ft)

Width (ft)

Thickness (in)

Waste buffer (%)

Bag size

40 lb50 lb60 lb80 lb

Price per cubic yard ($ (optional))

Volume

133.3 cu ft

Ready-mix (incl. waste)

5.43 cu yd

80 lb bags needed

245

Estimated cost

$815

Bags needed by bag size

Bag size	Bags needed
40 lb	489
50 lb	392
60 lb	326
80 lb	245

Includes a 10% waste buffer. Ready-mix concrete is typically sold in quarter- or half-yard increments. Round up when ordering.

Concrete alone, 10x10 to 30x40 at 4 inches

Every figure in this table is the material for a 4 inch slab with the site’s standard 10 percent waste allowance folded in, priced two ways: delivered ready-mix at $150 per cubic yard, a typical 2026 national figure, and 80 lb bags at $6.50 each, the middle of the typical retail range. Neither column includes delivery fees, base, steel, forms or anyone’s time.

Slab	Area	Cubic yards with 10% waste	Ready-mix at $150 a yard	80 lb bags	Bags at $6.50 each
10x10	100 sq ft	1.36	$204	62	$403
12x12	144 sq ft	1.96	$293	89	$579
16x20	320 sq ft	4.35	$652	196	$1,274
20x20	400 sq ft	5.43	$815	245	$1,593
24x24	576 sq ft	7.82	$1,173	353	$2,295
30x40	1,200 sq ft	16.3	$2,444	734	$4,771

The bag column is the bag count times the price: 245 bags for the 20x20 times $6.50 is $1,592.50, which rounds to $1,593. The ready-mix column is calculated from the volume before it was rounded to two decimals, so the 12x12 reads $293 where 1.96 times $150 on a pocket calculator gives $294; the dollar is rounding, not a different price.

Read across any row and the ratio holds: at 4 inches, ready-mix at $150 works out to about $2.04 per square foot of slab, and bags at $6.50 to about $4. The bag figure is the 45 bags that make a yard, explained in the bags per yard guide, scaled up with the waste allowance. Bags double the material cost at every size, and the right-hand columns are there mostly to show that a 16x20 in bags means 196 of them, each mixed by hand, which is not a slab anyone pours that way.

For 5 and 6 inch versions of these sizes, the patio slab guide carries the patios at 5 inches and the garage slab guide carries the 20x20 to 40x60 floors at 4, 5 and 6, and the calculator at the top of this page takes any size and your own per-yard quote.

What the plant charges per yard, and the fees around it

Delivered ready-mix in 2026 typically runs $120 to $180 per cubic yard across the US, and $150 is a fair planning figure where you do not yet have a quote. The spread is mostly region and haul distance. On top of the base price, a plant’s rate sheet usually carries a few per-yard adders: a higher strength mix (4,000 psi over 3,000), air entrainment for freeze-thaw exposure, fiber, and hot- or cold-weather admixtures. Each is small per yard, and they stack.

The fees that surprise people are flat, not per yard:

• Short-load fee. Below a minimum order, commonly 3 or 4 cubic yards, the plant adds a charge of typically $60 to $150, because a mixer and a driver cost it the same whether the drum holds 1.5 yards or 9. In the table that catches the 10x10 at 1.36 yards and the 12x12 at 1.96. On the 10x10 the fee can be most of the concrete bill over again.
• Standby time. The driver has an unloading allowance, and once it is used up the clock runs, billed by the minute or in quarter-hour blocks at a rate the quote should state. A crew still setting forms when the truck arrives pays it.
• Delivery, fuel and environmental surcharges. Small individually, listed separately, and worth adding up before comparing two plants.
• Saturday or after-hours delivery, where offered, at a premium.

Two more things about the order itself. Plants commonly take orders in quarter- or half-yard steps, so the 20x20 that needs 5.43 yards is ordered as 5.5, and the invoice is 5.5 times $150, or $825, not the $815 in the table. And a mixer carries a typical 9 to 10 yards, varying by supplier, so the 30x40 at 16.3 yards is two trucks, which means two delivery charges and a crew that can place the first load before the second arrives.

Bags at $5 to $8: when they still make sense

An 80 lb bag of standard mix retails in 2026 for typically $5 to $8, and 45 of them make a cubic yard, so a yard of bagged concrete is $225 to $360 before the water and a day of mixing. Against $120 to $180 delivered, the truck is roughly half the price per yard, and that gap only widens as the slab grows.

The short-load fee is what keeps the comparison alive at the small end. The 10x10 is $204 of ready-mix plus a fee of $60 to $150, so $264 to $354 at the curb, against $403 in 62 bags. The truck is still cheaper on paper, but it needs a route to the forms, a prepared site, and the whole slab placed and finished in the hour or so the mix allows. Bags let one or two people work at their own pace, which is why they stay the usual answer for an equipment pad, a landing, steps, or any pour under about a yard. Rent a mixer rather than fighting a wheelbarrow and a hoe past about 20 bags. A bagged slab still has to be placed continuously, because a batch that sets before the next one lands leaves a cold joint through the slab, and that is the real limit on bagging a 12x12 at 89 bags.

Installed at $6 to $12 per square foot

A contractor’s price for a finished slab, with excavation, base, forms, reinforcement, the concrete, placing, finishing and joints, commonly falls between $6 and $12 per square foot in 2026 for a plain broom-finished slab. The next table puts that range beside the concrete-only figure so the difference is visible.

Slab	Area	Concrete only at $150 a yard	Installed at $6 per sq ft	Installed at $12 per sq ft
10x10	100 sq ft	$204	$600	$1,200
12x12	144 sq ft	$293	$864	$1,728
16x20	320 sq ft	$652	$1,920	$3,840
20x20	400 sq ft	$815	$2,400	$4,800
24x24	576 sq ft	$1,173	$3,456	$6,912
30x40	1,200 sq ft	$2,444	$7,200	$14,400

The concrete is between a sixth and a third of the finished price. The rest is the base, the steel, the lumber, three or four people for most of a day, the finishing, and the contractor’s overhead and margin. Small slabs sit toward the top of the per-foot range because a crew, a truck and a set of tools cost the same to bring out for 100 square feet as for 400; large plain slabs sit toward the bottom.

Five things move a quote inside that range, or out of it:

• Thickness. Each inch over 4 adds a quarter of the concrete, so a 5 inch slab is about 25 percent more material and a 6 inch slab 50 percent more, plus a deeper excavation. The slab thickness guide covers which uses need it.
• Reinforcement. Welded wire mesh is the cheapest. A #4 rebar grid at 18 inches on a 20x20 is 28 sticks by the rebar calculator, typically $10 to $15 a stick at retail in 2026, plus chairs and tie wire and the time to tie it.
• Finish. Broom is the baseline. Exposed aggregate, color and stamping add material and skilled labor, and stamped work commonly runs $12 to $20 per square foot installed on its own.
• Access. A backyard slab behind a 36 inch gate is wheelbarrowed or pumped, and both cost labor or a pump fee. A driveway the truck can back onto is the cheap case.
• Region. Labor rates, frost footings, permit requirements and the concrete price itself all vary by state, and the same 20x20 can sit at the bottom of the range in one market and above the top of it in another.

The line items a concrete quote does not include

Whether you hire the slab or pour it yourself, these come out of a separate pocket from the concrete:

• Gravel base. Four inches of compacted crushed stone under a 20x20 is 4.94 cubic yards compacted, the same volume as the slab’s own exact figure, and the gravel calculator adds the compaction allowance and converts it to tons. Crushed stone at the yard typically runs $20 to $60 a ton in 2026, with $45 a fair planning figure, and delivery is on top, with a minimum that hurts small orders the way the short-load fee does.
• Vapor barrier. A 10 mil polyethylene sheet under the slab, lapped and taped. One of the cheapest items on the list and the one most often missing from a low bid.
• Rebar or mesh, with the chairs that hold it at mid-depth. The steel is in the previous section; the chairs are small money and a separate trip.
• Forms and stakes. A 20x20 perimeter is 80 linear feet of 2x4 for a 4 inch slab, plus stakes every 2 to 3 feet, form oil and a few screws. The lumber survives for a second pour.
• Pump. Where the truck cannot reach the forms, a line pump with an operator is hired by the half day, and the half-day minimum in 2026 typically runs several hundred dollars, more for a boom pump. It is the single biggest surprise on backyard slabs.
• Saw cuts. Control joints at roughly 8 to 12 feet in a 4 inch slab, tooled in during finishing or saw-cut the next day at a price per linear foot. A 20x20 wants one cut each way, 40 linear feet.
• Excavation and haul-off, grading, a permit where the building department wants one, curing compound, and a sealer if the slab will see salt.

Each item is small next to the concrete except the pump and the base. Together, on a 20x20, they commonly add several hundred dollars to the $815 of concrete, and past a thousand once a pump is involved, before anyone is paid to place it. The rest of the distance to the $2,400 to $4,800 installed figure is labor, finishing and the contractor’s margin.

Pouring a 10x10 yourself, hiring the 20x20

The honest line between the two is not price but the size of the window. A 10x10 is 1.36 yards, which two people can place, screed and float in an afternoon from bags or a short load, and a first-timer’s finish on a shed floor or a pad nobody looks at is fine. The saving against the $600 to $1,200 a contractor charges is real: the concrete is $204 to $403 depending on how it arrives, the base, forms and mesh add a modest amount on top, and the rest is a weekend.

A 20x20 is 5.43 yards. That has to be placed, struck off, bull-floated, edged, jointed and broomed in one continuous operation before it sets, and a truck that arrives with 5.5 yards does not wait for you to learn. Three experienced people make it look easy; two beginners produce a slab with a hump in the middle and a cold joint where they stopped for lunch. The $2,400 to $4,800 installed range buys the finish as much as the labor. The hybrid that works for a lot of people is to dig, build the base, set the forms and tie the steel yourself, then hire a finishing crew for the pour day and buy the concrete on your own account. The crew’s day rate is a fraction of the full installed price, and the parts you did are the parts with time rather than skill in them.

Reading a ready-mix quote and a contractor’s bid

A ready-mix quote is a short document and every line on it matters. It should name the strength in psi, the maximum aggregate size, the slump, whether the mix is air-entrained, and any fiber or admixture; then the price per yard, the minimum order and the short-load fee, the standby allowance in minutes and the rate after it, delivery and surcharges, and the washout arrangement. If a line is missing, ask, because the plant will charge for it either way. The concrete calculator takes the per-yard price from the quote and returns the material cost for your exact slab, waste included.

A contractor’s bid at a price per square foot is only comparable to another bid if both say what is inside the number. The bid should state the thickness, the mix strength, the base material and its compacted depth, the vapor barrier, the reinforcement and that it will be chaired, the finish, how and when control joints go in, whether excavation and haul-off are included, the form and stake allowance, a pump if access needs one, the permit, and cleanup. A bid that reads “4 inch slab, broom finish” at $6 a foot and one that reads the full list at $9 may be the same job at the same price once the first contractor’s extras arrive. Ask what happens on a rain day, what the charge is if the subgrade needs more fill than expected, and who pays if the truck waits. The answers tell you more about the finished slab than the per-foot number does.