Small Concrete Slab Cost for 10×10 to 20×20 Sizes in 2026

Small concrete slabs from 10×10 to 20×20 cost $600 to $4,800 in 2026 at $6 to $12 per square foot installed. The most common small slab sizes are 10×10 (AC pads and small shed bases), 12×12 and 12×16 (sheds and hot tub pads), and 16×20 (large patios and small garage pads). Smaller slabs have a higher cost per square foot because contractor minimum charges and setup costs are spread over less area. This guide provides exact pricing for every common small slab size so you can budget accurately.

10×10 and 10×12 Slab Costs

A 10×10 slab (100 sq ft) costs $600 to $1,200. It requires 1.23 cubic yards at 4 inches thick. Common uses include AC unit pads, small shed bases, and generator pads.

A 10×12 slab (120 sq ft) costs $720 to $1,440. It requires 1.48 cubic yards at 4 inches thick. This size is popular for storage sheds and outdoor utility pads.

Both sizes are small enough for confident DIY projects. Using bagged concrete mix (56 to 67 bags of 80-pound mix) lets you work at your own pace without the time pressure of ready-mix delivery. Professional installation carries a minimum charge of $800 to $1,200 at most contractors, so these small slabs often cost near the minimum regardless of size.

12×12 and 12×16 Slab Costs

A 12×12 slab (144 sq ft) costs $864 to $1,728. It requires 1.78 cubic yards at 4 inches thick. This is a common size for standard backyard sheds and workshop additions.

A 12×16 slab (192 sq ft) costs $1,152 to $2,304. It requires 2.37 cubic yards at 4 inches thick. The 12×16 size works for larger sheds, small workshops, and covered patio pads.

At these sizes, ready-mix delivery becomes more practical than bagged concrete. A 12×16 slab would require over 100 bags of 80-pound mix (over 4 tons of hand-mixing), making a 2.5 to 3 yard ready-mix delivery the better choice. Most batch plants have a minimum delivery of 1 to 3 yards with a short-load fee of $50 to $100 for small orders.

12×20, 14×14, and 16×16 Slab Costs

A 12×20 slab (240 sq ft) costs $1,440 to $2,880. It requires 2.96 cubic yards at 4 inches thick. Uses include large shed foundations, small patio areas, and workshop pads.

A 14×14 slab (196 sq ft) costs $1,176 to $2,352. It requires 2.42 cubic yards. This square size works for hot tub decks and small detached garages.

A 16×16 slab (256 sq ft) costs $1,536 to $3,072. It requires 3.16 cubic yards. This size handles small single-car garages, large hot tub surrounds, and medium patio pads.

16×20 and 20×20 Slab Costs

A 16×20 slab (320 sq ft) costs $1,920 to $3,840. It requires 3.95 cubic yards at 4 inches thick. This size is popular for covered patios, carport pads, and small workshop buildings.

A 20×20 slab (400 sq ft) costs $2,400 to $4,800. It requires 4.94 cubic yards. The 20×20 is the standard size for two-car garages and large patios. At 5 inches thick (garage standard), it needs 6.17 yards and costs $2,800 to $5,600.

At the 16×20 and 20×20 sizes, the per-square-foot cost drops toward the lower end of the $6 to $12 range because setup costs are spread over more area. These sizes represent the transition from small-project pricing to standard project pricing.

Which small slab size should I choose for a shed?

Match the slab to your shed size plus 1 to 2 feet on each side for overhang and access. A 10×12 shed needs at least a 10×12 slab. A 12×16 shed needs a 12×16 slab. If the slab will serve as the shed floor (no separate floor framing), size it exactly to the shed footprint. If using a separate floor frame, extend the slab 2 to 4 inches beyond the frame on each side.

How thick should a small concrete slab be?

Use 4 inches for light-duty applications (storage sheds, AC pads, walkways). Use 5 inches for vehicle parking pads and hot tub bases. Use 6 inches for heavy equipment pads and metal building foundations. Standard 3,000 PSI concrete with wire mesh or fiber reinforcement works for most small slab applications.

Frequently Asked Questions

Is it cheaper per square foot to pour a bigger slab?

Larger slabs cost less per square foot because setup, mobilization, and forming costs are spread over more area. A 10×10 slab may cost $10 to $12 per square foot while a 20×20 slab of the same specification costs $6 to $8 per square foot. Contractor minimum charges also make very small slabs disproportionately expensive.

Should I DIY or hire a pro for a small slab?

DIY works well for slabs under 100 square feet (10×10 or smaller) using bagged concrete mix. For slabs 100 to 200 square feet, DIY with ready-mix delivery is manageable with a helper. For slabs over 200 square feet, professional installation produces better results and is worth the labor cost. Factor in your time, tool rental, and the risk of a poor result when comparing DIY to professional pricing.

Do small slabs need rebar?

Wire mesh or fiber reinforcement is sufficient for most small slabs under 200 square feet used for light-duty applications. Use #3 rebar at 18 inches on center for slabs supporting heavy loads (hot tubs, vehicles, heavy equipment). Rebar adds $50 to $150 to small slab material cost and significantly improves crack resistance.

Concrete

10×10 (100 sq ft, installed)

$600

$1,200