Concrete Slab Cost in Colorado
Quick answer: a 4-inch concrete slab in Colorado costs about $6.50 – $12.50 per sq ft installed, 5% below the U.S. average. A 12 × 12 ft patio runs about $1,090 – $1,910, a 24 × 24 ft garage floor $4,070 – $7,270 and a 20 × 40 ft driveway $5,580 – $10,000.
Colorado prices sit a little below the national average in our model, with Denver close to average. Front Range builders deal with two things that add real cost: expansive bentonite clay, which can heave a slab several inches, and big temperature swings between day and night.
Concrete Prices in Colorado by Project
| Project | Colorado installed | Per sq ft | U.S. average | DIY materials |
|---|---|---|---|---|
| 12 × 12 ft patio | $1,090 – $1,910 | $7.50 – $13.50 | $1,130 – $1,970 | $500 – $730 |
| 10 × 12 ft shed slab | $940 – $1,630 | $7.50 – $14.00 | $970 – $1,680 | $450 – $640 |
| 20 × 20 ft slab | $2,700 – $4,890 | $6.50 – $12.50 | $2,810 – $5,060 | $1,070 – $1,710 |
| 24 × 24 ft garage floor (5 in) | $4,070 – $7,270 | $7.00 – $13.00 | $4,250 – $7,540 | $1,720 – $2,650 |
| 20 × 40 ft driveway (5 in) | $5,580 – $10,000 | $6.50 – $12.50 | $5,820 – $10,380 | $2,320 – $3,600 |
| 30 × 40 ft shop floor (6 in) | $8,800 – $15,540 | $7.00 – $13.00 | $9,190 – $16,140 | $3,910 – $5,830 |
4-inch slabs unless shown. Installed: forms, broom finish and labor, up to vapor barrier, #4 rebar and contractor overhead and profit. DIY: concrete (ready-mix or 80-lb bags, whichever is cheaper) and forms, up to vapor barrier and rebar. Excavation, gravel base and permits are extra.
Metro Areas
Prices in the biggest metro areas differ from the state as a whole, mainly because of labor costs.
| Area | Factor | Slab per sq ft | 12 × 12 patio | 24 × 24 garage | 20 × 40 driveway |
|---|---|---|---|---|---|
| Colorado (statewide) | 0.95 | $6.50 – $12.50 | $1,090 – $1,910 | $4,070 – $7,270 | $5,580 – $10,000 |
| Denver metro, CO | 0.97 | $6.50 – $12.50 | $1,110 – $1,930 | $4,140 – $7,380 | $5,680 – $10,150 |
Building a Slab in Colorado
| Weathering (IRC) | Severe statewide. |
|---|---|
| Concrete strength | 4,000 PSI air-entrained for driveways (de-icers are widely used); 3,500 PSI air-entrained minimum for patios and garage floors. 4,000 PSI ready-mix runs about $136 – $171 per yd³ here. |
| Frost depth | About 30 to 36 in along the Front Range; deeper in the mountains. |
| Soil | Expansive clay and bentonite along the Front Range. Many lots come with a soils report that says how slabs must be built, sometimes with over-excavation and replacement of the clay. |
| Pouring season | Late spring to early fall. Spring and fall nights can drop below freezing even after warm days, so fresh slabs may need blankets. |
- Read the soils report for your lot before pricing a slab: over-excavation and structural fill can cost more than the concrete.
- Garage and basement slabs in swelling soil are often "floating", separated from walls with an isolation joint so they can move.
- Use air-entrained concrete and seal outdoor slabs; magnesium chloride de-icers are hard on concrete.
Frost depths and permit rules are set by your city or county; check with the local building department before you dig. A permit for a small residential slab or driveway typically costs about $50 – $350.
Price Your Own Slab in Colorado
The calculator below starts at Colorado prices. Enter your size, thickness, finish and reinforcement; if you have local prices for ready-mix or labor, type them over the defaults.
Concrete Slab Cost & Volume Estimator
Precision multi-layer project budgeting: Materials, Sub-Base, Reinforcement, Labor & Equipment
Picking a location sets the ready-mix, excavation and labor rates below to that area's typical level. You can still type your own local prices afterwards. Slab prices by state.
Closer spacing uses more steel and raises the rebar cost.
Not charged when bagged concrete is selected.
A scaled plan of your slab: rebar grid at the spacing you chose, support chairs about every 3 to 4 ft, and the recommended control-joint saw cuts (2.5 times the thickness in inches, in feet, capped at 15 ft). It redraws as you change the inputs.
| Scope Item / Material Description | Amount |
|---|
Enter the total your contractor quoted. We compare it with a benchmark for the same slab and scope you set in the calculator: materials at your entered prices plus labor at the regional standard rate, before any overhead or profit. Make sure the calculator scope (base, rebar, finish, pump, demolition) matches what the bid includes.
Optional: enter the bid's line items to see where the markup sits
Enter the forecast for pour day. The check follows ACI 306R (cold weather) and ACI 305R (hot weather) and estimates the surface evaporation rate that drives plastic shrinkage cracking.
How These Prices Are Worked Out
These are modelled prices, not quotes collected from Colorado contractors. Each project is priced with the same line items as the slab cost calculator at national unit prices, then Colorado's location factor of 0.95 is applied to ready-mix concrete and labor, as the calculator does when you pick Colorado. Bagged concrete, forms, rebar and the delivery fee stay at national prices. The factors are approximate, set by our editors to reflect typical construction cost differences between states; the full method is in the 2026 concrete price report.
Have a quote already? Check it with the concrete quote checker, which uses the same factors.
Colorado Concrete Questions
About $6.50 to $12.50 per sq ft installed for a 4-inch slab with forms, a broom finish and labor, 5% below the national average. A 12 x 12 ft patio runs about $1,090 to $1,910 and a 24 x 24 ft garage floor (5 in) about $4,070 to $7,270. Excavation, gravel and permits are extra.
A 20 x 40 ft driveway, 5 inches thick with rebar and a broom finish, costs about $5,580 to $10,000 installed in Colorado ($6.50 to $12.50 per sq ft). Removing an old driveway and the street apron are extra.
About $128 to $152 per cubic yard for 3,000 PSI ready-mix before delivery fees, and about $136 to $171 for 4,000 PSI. Small loads add a short-load fee of $80 to $200 or more.
In the Denver area our model puts 3,000 PSI ready-mix at about $131 to $155 per cubic yard before delivery, and a 4-inch slab at about $6.50 to $12.50 per sq ft installed, 3% below the U.S. average. A 12 x 12 ft patio runs about $1,110 to $1,930 and a 20 x 40 ft driveway about $5,680 to $10,150.
Much of the Front Range sits on expansive clay and bentonite, which swell when they get wet. A slab poured on that soil can lift and crack. Builders follow the lot's soils report, which may require removing and replacing the clay, a thicker base, or a slab that is free to move.
They are the site's national cost model with Colorado's location factor (0.95) applied to ready-mix and labor, the same thing the calculator does when you pick Colorado. They are modelled estimates, not prices collected from Colorado contractors; get local quotes before you build.