Concrete Garage Floor Cost Calculator
Concrete garage floor installation costs $6–12 per square foot. A standard 20×20 two-car garage floor runs $2,400–$4,800 installed. Enter your garage dimensions below for a full material and labor estimate.
Pro Tips
- →Garage floor installation costs $6-12 per square foot for a standard broom finish
- →A standard 2-car garage (20x20 ft) costs $2,400-$4,800 installed
- →Upgrade to 5-inch thickness for heavy vehicles or workshop use — adds $0.50-1.00 per sq ft
- →Epoxy coating adds $2-5 per square foot but dramatically extends floor life
- →Control joints every 10-12 feet prevent cracking and are included in professional installs
Estimated concrete cost (materials + delivery) · For projects over 1 cubic yard, ready-mix is typically more economical and easier to work with.
245 bags × 80lb
5.43 cubic yards + delivery
400 sq ft × $3.00–$8.00/sq ft
Based on 2026 U.S. national pricing. Prices vary by location and time — contact local suppliers for accurate quotes.
That's typically a professional pour. See volume ↓
4 short emails from Dave: what a fair quote should land at for your slab, the scope changes that swing it ±$500, and whether DIY is actually cheaper at your volume. Reply anytime — he'll review your real quote.
Includes 10% waste factor
For general step-by-step instructions, read our complete Garage Floor Thickness and Garage Floor Epoxy Guide.
Garage Floor Cost by Size
Garage floors are among the most cost-effective concrete projects - large, flat, rectangular slabs with easy truck access and a simple broom finish. Installed price tracks square footage at $6-12/sq ft, the low end being a broom finish over good subgrade in low-cost regions and the high end thicker slabs, heavy reinforcement, or difficult access.
| Garage Type | Dimensions | Area | Installed Cost ($6-12/sq ft) |
|---|---|---|---|
| 1-car | 12x20 ft | 240 sq ft | $1,440-2,880 |
| 1.5-car | 16x20 ft | 320 sq ft | $1,920-3,840 |
| 2-car standard | 20x20 ft | 400 sq ft | $2,400-4,800 |
| 2-car wide | 22x22 ft | 484 sq ft | $2,904-5,808 |
| 2-car tandem | 12x40 ft | 480 sq ft | $2,880-5,760 |
| 3-car | 30x22 ft | 660 sq ft | $3,960-7,920 |
| Oversized workshop | 24x30 ft | 720 sq ft | $4,320-8,640 |
Most homeowners want a two-car floor, which lands at 400-440 sq ft. To turn your own footprint into a concrete volume and dollar figure, use the garage floor concrete calculator or the broader concrete cost calculator.
What's in the Price: 2-Car Floor Line Items
The table below breaks a standard 20x20 (400 sq ft) two-car floor into the line items a contractor actually prices. Site conditions - sloped lots, soft soil, or tear-out - push the total above this baseline.
| Item | Cost Range |
|---|---|
| Subgrade prep (grading, compaction) | $200-600 |
| Gravel base (4 in compacted) | $150-300 |
| 6-mil vapor barrier | $100-200 |
| Concrete (5.4 cu yd at 4 in) | $800-1,200 |
| Forming and placement labor | $500-900 |
| Broom finish and control joints | $300-600 |
| Overhead and margin | $350-1,000 |
| Total installed | $2,400-4,800 |
Labor is the largest variable: a crew of three can form, pour, and finish a 400 sq ft floor in a day, but that is still 18-24 labor hours. Tear-out of an old slab adds $2-4/sq ft, and a permit (often required for an attached garage) adds $50-200.
Slab Thickness: 4 Inches vs. 5-6 Inches
Four inches is standard for a floor parking ordinary vehicles. Step up to 5-6 inches when the load increases:
- You park heavy trucks, RVs, or vehicles over 6,000 lb
- You run a workshop with floor-standing machinery
- You plan a vehicle lift (which needs an engineered slab and often a thickened pad under the posts)
- Your subgrade has poor bearing capacity
| Thickness | Concrete per 400 sq ft | Added Installed Cost vs. 4 in | Typical Use |
|---|---|---|---|
| 4 in | 5.4 cu yd | baseline | Cars, light SUVs, normal use |
| 5 in | 6.7 cu yd | +$0.40-0.70/sq ft | Heavy pickups, light workshop |
| 6 in | 8.0 cu yd | +$0.80-1.40/sq ft | RVs, lifts, machinery, poor soil |
Per ACI 332-20 (residential concrete construction) and IRC R506.2.3, a residential slab-on-grade is a 4 in nominal minimum at 3,000 PSI - step up to 4,000 PSI in freeze-thaw climates. Reinforce with welded wire mesh or #4 rebar at 16 in on-center each way, set at mid-depth on chairs. See the garage floor thickness guide and rebar vs. mesh vs. fiber.
Subgrade, Vapor Barrier, and Control Joints
Three details separate a floor that lasts 50 years from one that cracks and sweats in five.
- Subgrade - 4-6 inches of compacted gravel over firm, well-drained soil spreads vehicle loads and prevents settlement. Skimping here causes cracking no amount of rebar fully fixes. See the subgrade preparation guide.
- Vapor barrier - a 6-mil (10-15 mil ideal) polyethylene sheet directly under the slab blocks ground moisture. Required for heated or attached garages, it is the difference between a coating that bonds and one that peels.
- Control joints - saw-cut to one-quarter of slab depth (1 in on a 4 in slab) within 6-12 hours, spaced 8-12 ft apart. A 20x20 floor is divided into four 10x10 panels.
- Slope to door - a slight 1/8 to 1/4 in per foot fall toward the overhead door drains wash water and snowmelt instead of pooling.
Coating Upgrades: Epoxy and Polyaspartic
A coating is the most common upgrade. Epoxy and polyaspartic systems both seal the concrete, resist oil and chemicals.
| Finish | Added Cost | Cure / Return to Service | Best For |
|---|---|---|---|
| Broom finish (standard) | - | n/a | Any garage |
| Epoxy coating | $3-7/sq ft | 24-72 hr | Workshop, general use |
| Polyaspartic/polyurea | $5-8/sq ft | Same day | Fast turnaround, UV-stable, most durable |
| Acid stain | $2-4/sq ft | 24-48 hr | Decorative showroom look |
| Polished concrete | $3-8/sq ft | n/a | High-end showroom |
A full-flake epoxy system on a 400 sq ft floor runs $1,200-2,800 installed; polyaspartic runs $2,000-3,200 but cures in a day and resists the UV yellowing that dulls epoxy near the door. DIY kits cut materials to $0.50-1.00/sq ft, but surface prep (grinding or acid etching) makes or breaks adhesion. See the garage floor epoxy guide first.
DIY vs. Hiring a Contractor
A 400 sq ft floor sits at the upper limit of a practical DIY pour. You will need ready-mix delivery (5+ yards is too much for bagged mix), two to three helpers, the right tools (screed, bull float, trowel, edger, groover/saw), and the discipline to cut control joints within hours of finishing. Realistic DIY savings are $500-1,500 on a two-car floor - against the risk of a wavy, weak surface you look at every day. If you have never poured a slab, practice on a shed base first.
Ready to price your floor? Enter your garage dimensions in the calculator above for an exact concrete volume and installed cost, then compare finishes for your final number.