Garage Floor Concrete Slab Cost in 2026: 1-Car, 2-Car & 3-Car Prices
Garage slabs cost more than patios because they are normally poured at 6 inches with a rebar grid. 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 is held up on chairs rather than laid flat on the ground, where it does almost nothing. IRC R506.2.4 is the benchmark to quote at a contractor: where reinforcement is provided it must be supported so it stays “from the center to upper one-third of the slab” throughout the pour, which on a 6-inch garage floor means roughly 3 to 4 inches up from the base.
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 | IRC R506.2.3 exempts unheated garages; specify it if yours is heated |