Garage Floor Concrete Slab Cost in 2026: 1-Car, 2-Car & 3-Car Prices
Garage slabs cost more than patios because they require 6-inch thickness and rebar reinforcement. 1-car garage: $1,440–$4,320 · 2-car (24×24): $3,456–$10,368 · 3-car: $6,480–$19,440
Garage Slab Cost Calculator
Concrete Slab Cost Calculator
Garage Slab Cost by Configuration
| Configuration | Sq Ft | Low | Mid | High | Notes |
|---|---|---|---|---|---|
| 1-car small (12×20) | 240 | $1,440 | $2,880 | $4,320 | Tight 1-car, no workspace |
| 1-car standard (14×22) | 308 | $1,848 | $3,696 | $5,544 | Comfortable 1-car |
| 1-car large (16×24) | 384 | $2,304 | $4,608 | $6,912 | 1-car with workspace |
| 2-car standard (20×20) | 400 | $2,400 | $4,800 | $7,200 | Tight 2-car |
| 2-car comfortable (24×24) | 576 | $3,456 | $6,912 | $10,368 | Standard 2-car garage |
| 2-car large (24×30) | 720 | $4,320 | $8,640 | $12,960 | 2-car with workshop |
| 3-car (30×24) | 720 | $4,320 | $8,640 | $12,960 | Standard 3-car |
| 3-car large (30×36) | 1080 | $6,480 | $12,960 | $19,440 | 3-car with storage |
| RV garage (14×45) | 630 | $3,780 | $7,560 | $11,340 | Single RV bay |
| RV + car (24×45) | 1080 | $6,480 | $12,960 | $19,440 | RV + 1 car |
All estimates based on 6-inch slab with rebar reinforcement. Mid = national average installed including labour, forming, and broom finish. Excludes apron, permits, and epoxy coating.
Why Garage Slabs Cost More Than Patios
- 6-inch thickness: Garages require 50% more concrete than a 4-inch patio slab. Extra concrete = $1–$2/sqft more in material cost.
- Rebar grid: Unlike patios (which can use wire mesh), garage floors need rebar. Labour to place and tie rebar adds $1.50–$2.50/sqft.
- Heavier forming: 6-inch forms are more robust than 4-inch, adding setup time.
- Concrete volume: A 24×24 garage at 6-inch = 5.33 cubic yards vs 3.56 at 4-inch. Ready-mix costs scale with volume.
- Floor drain option: If adding a trench drain or floor drain, this is done during the pour and adds $1,500–$4,000.
Don’t Skip the Rebar
Some contractors offer “wire mesh garage slabs” at a lower price. This is false economy — vehicles exert point loads on the slab surface that wire mesh cannot adequately handle. Under heavy loads, wire mesh slabs develop cracking patterns that spread quickly.
Insist on rebar (#3 bar minimum, 18-inch on center) and verify it’s elevated 2 inches from the bottom with chairs — not lying flat on the ground where it provides minimal reinforcement.
Additional Garage Costs
| Item | Cost Range | Notes |
|---|---|---|
| Concrete apron (at door) | $500–$2,000 | 4–8 ft deep × door width |
| Floor drain / trench drain | $1,500–$4,000 | Requires plumbing connection |
| Radiant in-slab heating | $8–$20/sqft additional | Must be planned before pour |
| Epoxy floor coating | $2–$6/sqft | Applied after concrete cures; not part of slab |
| Existing slab removal | $2–$6/sqft | Jack-hammer + disposal; add if replacing |
| Building permit | $75–$300 | Required in most jurisdictions for new garage |
| Vapor barrier | $0.10–$0.25/sqft | Often required under garage slabs |