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SlabCosts
Prices updated January 2026

Garage Concrete Slab Cost

What it costs to pour a garage floor in 2026 — by size and thickness, materials or installed.

Garage slab cost calculator

Preset to a typical garage at 24×24 @ 4". Adjust anything — cost updates live.

Waste & region

Order extra for spillage & uneven subgrade. 10% is typical.

Installed cost estimate

$3,168 – $6,912

576 sq ft · 7.82 yd³ concrete

Bags of concrete needed (rounded up)

352

80 lb

470

60 lb

564

50 lb

704

40 lb

Ready-mix (delivered)
$1,038 – $1,661
Bagged mix (80 lb, DIY)
$1,936 – $3,168
Installed by a pro
$3,168 – $6,912

Estimate only — not a quote. Bag counts are rounded up and include a 10% waste allowance.

Installed $3,168 – $6,912

Garage slab sizes & cost

Size Concrete (4") Installed cost
16×20 · one-car garage 4.35 yd³ $1,760 – $3,840
20×20 · two-car garage 5.43 yd³ $2,200 – $4,800
20×24 · two-car garage 6.52 yd³ $2,640 – $5,760
24×24 · two-car garage 7.82 yd³ $3,168 – $6,912
24×30 · garage / shop 9.78 yd³ $3,960 – $8,640
Building the whole thing? Follow the garage guide Base → rebar → pour → cost, chained step by step for your size.

You'll also need

Sized for this exact slab — tap any item to open its calculator with your measurements already filled in.

Gravel base

8.18 yd³

4" compacted base under the slab

≈ $245 – $532

Open calculator
Rebar

41 sticks

#4 bar, 18" grid (34 bars)

≈ $287 – $533

Open calculator
Bedding sand

1.78 yd³

~1" leveling layer

≈ $50 – $103

Open calculator

Garage concrete slab cost

A garage floor is one of the most common slab pours, and one of the most forgiving to budget for because the sizes are standard. The big cost levers are thickness (4" for cars, 6" for trucks or a lift) and reinforcement — a garage slab really should have rebar or mesh.

Use the calculator above with your exact footprint, then follow the "You'll also need" cards to size the gravel base and rebar. If you're pouring the slab as part of a full build, price the 24×24 and 20×20 sizes — the two most common two-car footprints.

Prices updated January 2026 National US averages · reviewed quarterly

Volumes use standard bag yields and a 10% waste allowance; costs are national US averages that vary by region, mix and finish. See our methodology for exactly how each figure is worked out, or check the reference sources:

Slab cost by project

Concrete Slab Cost Cost per sq ft + calculator Garage Slab Cost Typical 20×20 / 24×24 Driveway Slab Cost Concrete vs asphalt Patio Slab Cost 10×10 to 20×20 Shed Base Cost Small pads

Frequently asked questions

How much does a garage concrete slab cost?
A two-car garage slab (about 20×20 to 24×24) costs roughly $2,200–$6,900 installed at 4–6" thick in 2026. Garage floors are usually poured at least 4"; go to 6" if you'll park heavy trucks or use a lift.
How thick should a garage floor be?
Four inches is the minimum for a residential garage. Most builders pour 4" for cars and 5–6" for heavier vehicles, workshops or lifts, often with rebar or wire mesh.
What size is a typical garage slab?
A one-car garage is around 12×20 to 16×20; a two-car garage is commonly 20×20, 20×24 or 24×24. Pick your exact size from the table for its full cost.
Does a garage slab need rebar?
Yes — a garage floor carries concentrated wheel loads, so rebar or welded wire mesh is strongly recommended. The "You'll also need" cards size the rebar grid for your slab.