Concrete Slab Cost Calculator: Find Your Price by Size (2026)
A 20×20 ft (400 sq ft) slab, 4 inches thick with wire mesh on a stone base, costs $2,180 to $5,620 installed, typically $3,360, at national prices read in October 2026. Change the size, thickness, steel, removal and state below and every cost line updates with its source.
Concrete Slab Cost Calculator, Line by Line
20 x 20 ft = 400 sq ft at 4 inches: $5.45 to $14.06 per sq ft installed.
| Line and source | Low | Typical | High |
|---|---|---|---|
Ready-mix concrete 4.94 cu yd plus 5 to 10% overage, 3,000 PSI at Supreme Concrete $127.05, Minimix Concrete $136.00, Gehring Construction & Ready-Mix $148.00, Scenic City Ready Mix $165.00 a yard | $659 | $754 | $896 |
Delivery and small-load fees Per-truck and short-load charges on the same four price lists | $0 | $35 | $419 |
Crushed-stone base, 4 in Crusher run from D & L Supply, JMJ Companies, Golden Landscaping Supply, Yard Works Landscape Supply | $261 | $325 | $443 |
Wire mesh (6x6 10-gauge) Menards online price, read 13 Oct 2026 | $96 | $96 | $96 |
Form boards Menards lumber, shared across reuses | $30 | $45 | $61 |
Crew labour Crew hours (our estimate) x BLS OEWS national wages, May 2025 x BLS employer costs (June 2026): $29.60 to $43.77 a crew hour | $770 | $1,332 | $2,101 |
Overhead and margin Our estimate: 20% to 40% of direct cost | $363 | $776 | $1,606 |
Low uses the cheapest published price and our lowest assumption on every line, high the dearest. The region changes crew wages only: no state-level ready-mix price is published, so concrete and materials stay at the four price lists. Not included: excavation, permits, pumping, sealing. Totals are rounded to the nearest $10.
Removal source: Village of River Forest, IL, 2026 Curb and Sidewalk Replacement bid tabulation (3 December 2025), read 14 October 2026. State wages: BLS OEWS May 2025 state data file, read 14 October 2026. Every other input is listed in the method block below.
How to Read This Table
- 4-inch mesh: 4-inch, 3,000 PSI, wire mesh, broom finish, 4-inch stone base. Patios, walkways, shed pads.
- 6-inch rebar: 6-inch, 4,000 PSI, #4 rebar at 18 inches, broom finish, 4-inch stone base. Driveways and garage floors.
- Typical uses median published prices and wages; the range runs from every lowest input to every highest.
- All estimates include labour, overhead and margin. Exclude: excavation, permits, decorative finishes, demolition.
- National prices. In the calculator, the state option changes crew wages only (BLS OEWS May 2025 state data).
Complete Concrete Slab Cost Table
| Slab Size | Sq Ft | 4-inch mesh, typical | 4-inch mesh, low to high | 6-inch rebar, typical | 6-inch rebar, low to high | Cu Yds (4“) | Cu Yds (6“) | Typical Use |
|---|---|---|---|---|---|---|---|---|
| 8×8 | 64 | $1,160 | $660 to $2,520 | $1,380 | $820 to $2,820 | 0.79 | 1.19 | Shed pad, AC unit |
| 8×10 | 80 | $1,270 | $730 to $2,680 | $1,540 | $930 to $3,050 | 0.99 | 1.48 | Small shed pad |
| 10×10 | 100 | $1,410 | $830 to $2,880 | $1,750 | $1,080 to $3,210 | 1.23 | 1.85 | Small shed, hot tub |
| 10×12 | 120 | $1,550 | $920 to $3,080 | $1,950 | $1,220 to $3,500 | 1.48 | 2.22 | Shed / storage |
| 12×12 | 144 | $1,710 | $1,030 to $3,330 | $2,200 | $1,400 to $3,850 | 1.78 | 2.67 | Patio / storage |
| 10×16 | 160 | $1,820 | $1,110 to $3,350 | $2,360 | $1,510 to $4,080 | 1.98 | 2.96 | Single car parking |
| 12×16 | 192 | $2,040 | $1,260 to $3,670 | $2,680 | $1,740 to $4,550 | 2.37 | 3.56 | Small patio |
| 14×14 | 196 | $2,070 | $1,280 to $3,710 | $2,720 | $1,770 to $4,610 | 2.42 | 3.63 | Patio |
| 10×20 | 200 | $2,100 | $1,300 to $3,760 | $2,770 | $1,800 to $4,670 | 2.47 | 3.7 | Small patio |
| 12×20 | 240 | $2,370 | $1,490 to $4,160 | $3,070 | $2,020 to $5,250 | 2.96 | 4.44 | Standard patio |
| 16×16 | 256 | $2,480 | $1,560 to $4,320 | $3,230 | $2,140 to $5,340 | 3.16 | 4.74 | Medium patio |
| 12×24 | 288 | $2,700 | $1,710 to $4,640 | $3,560 | $2,370 to $5,810 | 3.56 | 5.33 | Patio / parking |
| 16×20 | 320 | $2,920 | $1,800 to $4,960 | $3,880 | $2,600 to $6,270 | 3.95 | 5.93 | Large patio |
| 18×18 | 324 | $2,940 | $1,820 to $5,000 | $3,920 | $2,620 to $6,330 | 4 | 6 | Medium patio |
| 16×24 | 384 | $3,260 | $2,100 to $5,460 | $4,530 | $3,050 to $7,200 | 4.74 | 7.11 | Large patio |
| 20×20 | 400 | $3,360 | $2,180 to $5,620 | $4,690 | $3,170 to $7,430 | 4.94 | 7.41 | Large patio / small garage |
| 20×24 | 480 | $3,910 | $2,550 to $6,420 | $5,500 | $3,740 to $8,590 | 5.93 | 8.89 | Patio / sport court |
| 24×24 | 576 | $4,560 | $3,000 to $7,390 | $6,510 | $4,420 to $10,560 | 7.11 | 10.67 | 2-car garage floor |
| 20×30 | 600 | $4,730 | $3,120 to $7,630 | $6,750 | $4,590 to $10,910 | 7.41 | 11.11 | Large patio / RV pad |
| 24×30 | 720 | $5,540 | $3,680 to $8,830 | $7,960 | $5,450 to $12,640 | 8.89 | 13.33 | Large garage |
| 30×30 | 900 | $6,810 | $4,520 to $11,210 | $9,770 | $6,730 to $15,240 | 11.11 | 16.67 | Large garage / workshop |
| 24×40 | 960 | $7,220 | $4,800 to $11,820 | $10,370 | $7,150 to $16,110 | 11.85 | 17.78 | 3-car garage |
| 30×40 | 1,200 | $8,850 | $5,920 to $14,210 | $12,830 | $8,860 to $20,160 | 14.81 | 22.22 | 3-car garage / outbuilding |
| 30×50 | 1,500 | $10,890 | $7,330 to $17,800 | $15,840 | $10,990 to $25,070 | 18.52 | 27.78 | Workshop / outbuilding |
| 40×60 | 2,400 | $17,080 | $11,520 to $27,360 | $24,950 | $17,370 to $38,620 | 29.63 | 44.44 | Small commercial |
| 40×80 | 3,200 | $22,550 | $15,260 to $35,930 | $33,070 | $23,050 to $51,310 | 39.51 | 59.26 | Commercial / large garage |
Worked Example: 20×20 Concrete Slab
A 20×20 ft slab is one of the most common residential sizes, large patio, single-car garage, or sport court pad.
- As a patio: 4-inch, wire mesh, broom finish = $2,180 to $5,620, typically $3,360.
- As a garage floor: 6-inch, 4,000 PSI, rebar grid = $3,170 to $7,430, typically $4,690. The usual spec for vehicle loads (the model building code does not require reinforcement).
- As a light-duty driveway: 4-inch, 4,000 PSI, wire mesh = $2,210 to $5,700, typically $3,410. Many contractors pour driveways at 6 inches with rebar, the garage-floor price above.
Standard Sizes by Project Type
| Project | Standard Size | Approx Sq Ft |
|---|---|---|
| Small shed pad | 8×10 | 80 |
| Hot tub base | 10×10 | 100 |
| AC unit pad | 3×3 to 4×4 | 9–16 |
| 1-car garage | 12×20 or 14×20 | 240–280 |
| 2-car garage | 20×20 or 24×24 | 400–576 |
| Small patio | 10×12 to 12×16 | 120–192 |
| Standard patio | 12×20 to 16×20 | 240–320 |
| Large patio | 16×24 to 20×30 | 384–600 |
| RV parking pad | 12×40 to 16×50 | 480–800 |
| 3-car garage | 30×24 to 30×36 | 720–1080 |
Cubic Yards Quick Reference
Formula: (Length × Width × Thickness inches ÷ 12) ÷ 27 = cubic yards. Our model orders 5 to 10% extra; the last two columns show the 10% allowance.
| Slab Size | 4-inch slab | 6-inch slab | 4” + 10% | 6” + 10% |
|---|---|---|---|---|
| 8×8 ft | 0.79 | 1.19 | 0.87 | 1.31 |
| 10×10 ft | 1.23 | 1.85 | 1.35 | 2.04 |
| 10×16 ft | 1.98 | 2.96 | 2.18 | 3.26 |
| 10×20 ft | 2.47 | 3.7 | 2.72 | 4.07 |
| 12×12 ft | 1.78 | 2.67 | 1.96 | 2.94 |
| 12×16 ft | 2.37 | 3.56 | 2.61 | 3.92 |
| 12×20 ft | 2.96 | 4.44 | 3.26 | 4.88 |
| 14×14 ft | 2.42 | 3.63 | 2.66 | 3.99 |
| 16×16 ft | 3.16 | 4.74 | 3.48 | 5.21 |
| 16×24 ft | 4.74 | 7.11 | 5.21 | 7.82 |
| 18×18 ft | 4 | 6 | 4.40 | 6.60 |
| 20×20 ft | 4.94 | 7.41 | 5.43 | 8.15 |
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 20 x 20 ft (400 sq ft) slab (4-inch, 3,000 PSI, wire mesh, broom finish, 4-inch stone base).
| Line | Low | Typical | High | Basis |
|---|---|---|---|---|
| Ready-mix concrete | $659 | $754 | $896 | 4.94 cu yd plus 5 to 10% overage, at published per-yard prices |
| Delivery and small-load charges | $0 | $35 | $419 | Per-truck charges from the same price lists (10 yd per truck) |
| Crushed-stone base | $261 | $325 | $443 | 4 in compacted crusher run |
| Reinforcement | $96 | $96 | $96 | 6x6 10-gauge mesh panels, lapped |
| Form lumber | $30 | $45 | $61 | Perimeter boards, shared across reuses |
| Crew labour | $770 | $1,332 | $2,101 | Crew hours x BLS wages x employer costs |
| Overhead and margin | $363 | $776 | $1,606 | 20% to 40% on direct cost |
| Installed total | $2,180 | $3,360 | $5,620 | 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 mesh, rebar, lumber and poly prices. All read 13 October 2026. Crew hours, overage, overhead and margin are our estimates and are listed in the method above.