Cost to Pour a 100 Sq Ft Concrete Slab: $830 to $2,880
A 100 sq ft concrete slab, poured 10x10 at 4 inches with wire mesh on a 4-inch crushed-stone base and broom-finished, costs about $1,410 installed. From the lowest published prices to the highest the range is $830 to $2,880. It takes 1.23 cubic yards of concrete, or 56 bags of 80 lb mix, which is why this is the size where pouring it yourself is realistic.
Fixed Costs Dominate at This Size
Multiplying a per-square-foot rate quoted for a big slab by 100 gives a figure no contractor will match. Our model prices a 20x20 slab of the same spec at $8.41 per sq ft; the 10x10 comes out at $14.09. Two things cause the gap.
First, the crew’s fixed work: layout, setting up, stripping the forms and cleaning up take the same time on a small pad as on a patio. We allow 8 to 16 crew hours per job, and on a 10x10 crew labour is about 61% of the direct cost. Second, small-load charges: the order here is about 1.29 to 1.35 yards, under every threshold on the price lists we use (Gehring $50 under 4 yards; Scenic City $100 at 5 yards or less and another $100 at 2 yards or less). Concrete and delivery for this pad come to $215 to $843.
That is why bundling saves money. Added to a 20x20 slab poured the same day (making it 20x25), the extra 100 sq ft costs about $690 in our model, against about $1,410 as a job of its own. If you have a pad to pour and a patio, walkway or driveway planned, price them together.
10x10, 8x12, or 5x20: Which Shape for the Use
| Shape | Forms | Typical | Low to high | Suits |
|---|---|---|---|---|
| 10 x 10 | 40 ft | $1,410 | $830 to $2,880 | AC, generator or hot tub base, small shed |
| 8 x 12 | 40 ft | $1,380 | $810 to $2,840 | Shed or garden-store pad (96 sq ft) |
| 5 x 20 | 50 ft | $1,420 | $830 to $2,890 | Walkway or side path |
Same spec in every row (4-inch, mesh, stone base, broom finish). The strip needs a quarter more form board and more passes with the screed, but at this size the difference is small. For a do-it-yourself pour the square is the easiest shape to strike off level in one pass.
Pouring a 100 Sq Ft Pad Yourself: What to Buy
- Concrete: 1.23 cubic yards (33.3 cubic feet) at 4 inches. At the yields on the QUIKRETE Concrete Mix data sheet (0.60 cubic feet per 80 lb bag, 0.45 per 60 lb bag) that is 56 bags of 80 lb or 75 bags of 60 lb, plus a few spare for spillage. We could not read a current bag price from a national retailer on 13 October 2026, so we do not quote one here: multiply the count by your store’s shelf price.
- Stone base: a 4-inch compacted base is 1.23 cubic yards in place, about 1.48 yards loose. At four suppliers’ published crusher-run prices that is $65 to $111 before delivery.
- Forms: 40 ft of edge is 3 boards of 2x4x16 at Menards’ $12.13 each, $36.39, plus stakes and screws.
- Mesh (optional): 4 panels of 4x8 ft 6x6 10-gauge mesh, lapped, at $6.99 each, $27.96.
- Tools: a plate compactor, a mixer if you use bags, a screed board, floats, an edger and a groover. Rental rates are on the DIY tool rental page.
Bagged vs Ready-Mix Delivery at 100 Sq Ft
This is the size where the choice is genuinely open. Ready-mix for about 1.35 yards, priced from the four published lists we use with their small-load and truck charges, comes to $215 to $843, and it is placed in one go, so the whole pad sets up evenly. Bags spread the work over hours of mixing: 56 bags is about 4,480 lb to lift, mix and place, and the first batches start to stiffen before the last ones go in unless you have helpers and a mixer.
The truck has its own limits: it needs firm access close to the forms (or a pump, which costs extra), and it arrives in a delivery window, so the base, forms and mesh must be ready beforehand. Behind a narrow side gate or across a soft lawn, bags are often the only practical route.
The DIY Cutoff: When 100 Sq Ft Is Too Much to Pour Yourself
Three things decide it. Physical capacity: 4,480 lb of bagged mix is a lot of lifting in one session. Time: once the concrete is placed it has to be struck off, floated and edged before it stiffens, which is hard alone on a first pour. And the use: a pad that must stay dead level for equipment (a hot tub, a standby generator) or that the equipment maker sets a specification for is worth having a contractor pour. A shed or AC pad tolerates small imperfections and makes a better first project.
If you hire, expect a small pad to price well above the per-square-foot rate you see for patios, for the reasons above, and get more than one quote. The DIY slab guide has a fuller go or no-go checklist, and the AC pad and hot tub pad pages cover those uses.
How We Price a Slab
Every installed price on this site comes from one model: published ready-mix and materials prices, plus crew hours priced at Bureau of Labor Statistics wages, plus overhead and margin. The low figure uses the lowest published input and our lowest assumption at every step; the high figure uses the highest. The crew hours, overage and margin are our own estimates, not published figures, and are listed below so you can check them against your quote. Worked example: a 10 x 10 ft (100 sq ft) pad (4-inch, 3,000 PSI, wire mesh, broom finish, 4-inch stone base).
| Line | Low | Typical | High | Basis |
|---|---|---|---|---|
| Ready-mix concrete | $165 | $188 | $224 | 1.23 cu yd plus 5 to 10% overage, at published per-yard prices |
| Delivery and small-load charges | $50 | $110 | $619 | Per-truck charges from the same price lists (10 yd per truck) |
| Crushed-stone base | $65 | $81 | $111 | 4 in compacted crusher run |
| Reinforcement | $24 | $24 | $24 | 6x6 10-gauge mesh panels, lapped |
| Form lumber | $15 | $23 | $30 | Perimeter boards, shared across reuses |
| Crew labour | $370 | $657 | $1,050 | Crew hours x BLS wages x employer costs |
| Overhead and margin | $138 | $325 | $823 | 20% to 40% on direct cost |
| Installed total | $830 | $1,410 | $2,880 | Rounded to the nearest $10 |
Not included: excavation and soil haul-off, removing an old slab, permits, pumping, decorative finishes and sealing. Totals are national; the calculators’ state option swaps in that state’s BLS wages and leaves concrete and materials at the published lists.
Published inputs (read 13 October 2026)
- Ready-mix, per cubic yard: 3,000 PSI $127.05 to $165.00, 4,000 PSI $132.00 to $175.00, from Supreme Concrete (Los Angeles, CA), Minimix Concrete (Pequannock, NJ), Gehring Construction & Ready-Mix (Columbus, NE, list dated 2026-01-01), Scenic City Ready Mix (Tennessee, list dated 2024-08-03).
- Small orders and trucks: short-load charge $50 under 4 yd (Gehring) or $100 at 5 yd or less, plus $100 more at 2 yd or less (Scenic City); per truck, no charge within 20 miles (Gehring), a $35 surcharge (Scenic City), or $363.88 Zone A delivery plus a $55 environmental fee (Supreme).
- Crushed-stone base: $44.00 to $74.75 per cubic yard from D & L Supply (Central New York, $44.00/yd), JMJ Companies (Lynchburg, VA, $39.50/ton), Golden Landscaping Supply (Cumming, GA, $50.00/ton), Yard Works Landscape Supply (Fort Mill, SC, $74.75/yd); per-ton prices converted at 2,450 lb per yard.
- Steel, forms, poly: #4 rebar 20 ft $8.99, 6x6 10-gauge mesh 4x8 panel $6.99, 2x6x12 $14.32, 2x4x16 $12.13, 6-mil poly 8 ft 4 in x 100 ft $59.99, rebar chair $0.33 (Menards online prices; Home Depot and Lowe’s pages could not be read that day). That works out to $0.24 per sq ft for mesh and $0.74 per sq ft for a rebar grid, materials only.
- Wages: BLS OEWS 47-2051 cement masons (May 2025) 25th percentile $22.60, median $27.41, 75th $32.15 an hour; 47-2061 construction laborers $18.57, $22.66, $28.72. Employer costs from BLS ECEC June 2026, construction industry ($51.96 total compensation per $36.13 of wages, x1.44): a crew hour costs $29.60 to $43.77.
Our assumptions (estimates, not published figures)
- Crew: half cement masons, half laborers.
- Setup per job: 8 to 16 crew hours (layout, stripping, cleanup).
- Per 100 sq ft: 4-inch 4 to 7 crew hours, 6-inch 5 to 8.5, 8-inch 6 to 10; add 0.5 to 1 for mesh or 1.5 to 2.5 for rebar.
- Concrete overage 5% to 10%; base stone ordered at 1.2x its compacted volume; form boards charged at half to all of their price.
- Overhead and margin 20% to 40% of direct cost.
- 6-inch and thicker slabs use 4,000 PSI mix; thinner slabs 3,000 PSI.
Sources: BLS OEWS 47-2051 cement masons (May 2025), BLS OEWS 47-2061 construction laborers (May 2025), BLS ECEC, construction (June 2026), ready-mix price lists from Supreme Concrete, Minimix Concrete, Gehring Construction & Ready-Mix, Scenic City Ready Mix, crusher-run prices from D & L Supply, JMJ Companies, Golden Landscaping Supply, Yard Works Landscape Supply, Menards lumber and mesh prices, QUIKRETE Concrete Mix (No. 1101) data sheet, IRC R105.2. All read 13 October 2026. Crew hours, overage, overhead and margin are our estimates and are listed in the method above.