How Much Does a 10x20 Concrete Slab Cost?
A 10x20 concrete slab costs $1,200–2,400 installed at $6–12 per square foot. At 200 square feet it is the go-to size for a 10x20 shed, a single parking pad, or a narrow patio, and it takes 2.72 cubic yards of concrete at 4 inches with waste. That volume sits just under most ready-mix minimums, so short-load fees and contractor minimums shape the price more than on bigger slabs.
A 10x20 concrete slab costs $1,200–2,400 installed — 200 square feet at the typical $6–12 per square foot. It's small enough that the fixed costs of any concrete job (mobilization, forms, a truck trip) take a bigger share of the bill than they do on a garage-sized slab. Check your exact dimensions and region in the concrete cost calculator.
What a 10x20 Slab Is Usually For
- Shed base. A 10x20 is a common large-shed and workshop-shed footprint. Four inches on a compacted gravel base is standard; the shed base cost calculator prices sheds at $6–11 per sq ft installed.
- Single parking pad or carport. Ten feet is the minimum practical width for one car with doors opening. Pour 5 inches with #4 rebar if it will carry a vehicle.
- Narrow patio or hot tub pad. A 10x20 runs the length of a typical house wall. Four inches handles furniture and grills; see the patio cost calculator for decorative finishes.
The 200-Square-Foot Permit Line
A 10x20 is exactly 200 square feet, which matters for sheds. The model building code (IRC R105.2) exempts one-story detached accessory structures of 200 square feet or less from a building permit, so a 10x20 shed sits right at the limit. Many cities and counties set a lower threshold — often 120 square feet (10x12) — and zoning setbacks apply even when a permit doesn't. Check before you form. Our permit requirements guide covers what usually triggers one.
How Much Concrete a 10x20 Slab Takes
| Thickness | Cubic Yards (exact) | With 10% Waste | 80-lb Bags | Ready-Mix at $165–205/yd | Weight in Place |
|---|---|---|---|---|---|
| 4 in | 2.47 | 2.72 | 123 | $448–557 | 10,000 lb |
| 5 in | 3.09 | 3.40 | 153 | $560–696 | 12,500 lb |
| 6 in | 3.70 | 4.07 | 184 | $672–835 | 15,000 lb |
At 4 inches you're ordering under 3 yards, below the 3–4 yard minimum many plants set. Expect a short-load fee of $50–100 on top of the per-yard price — see the concrete cost per yard guide for how suppliers charge small orders. Bagged concrete avoids the fee, but 123 bags is a long day of mixing and risks cold joints between batches.
10x20 Slab Cost in Four Cities
These ranges come from our patio cost by city data at 200 square feet:
| Metro | Installed $/sq ft | 10x20 Slab (200 sq ft) |
|---|---|---|
| Houston, TX | $4.97–8.71 | $994–1,742 |
| Boston, MA | $7.54–13.88 | $1,508–2,776 |
| Charlotte, NC | $8.02–15.48 | $1,604–3,096 |
| Denver, CO | $8.05–14.28 | $1,610–2,856 |
On a job this size, many contractors quote a flat minimum rather than a per-foot rate, so the low end of a city's range is harder to hit than it is on a larger slab.
Base, Rebar, and Joints
- Gravel base: 4 inches of compacted stone under 200 sq ft is 2.47 cubic yards — about 3.5 tons, $62–123 at $25–50 per yard.
- Rebar: A shed or patio can use #3 bar on 18–24-inch centers or wire mesh. For a parking pad, #4 at 18 inches each way is about 280 linear feet ($210–420).
- Control joints: One joint across the middle splits the slab into two 10x10 panels — the ideal square panel for a 4-inch slab.
DIY vs. Contractor for a 10x20 Slab
This is the upper edge of reasonable DIY. Materials for a 4-inch slab run roughly $770–1,200: ready-mix ($448–557) plus a short-load fee ($50–100), gravel ($62–123), and rebar or mesh ($210–420), before forms and tool rental. That's up to half the $1,200–2,400 installed price. Our DIY vs contractor guide calls a 10x10 manageable with research and helpers; a 10x20 is twice that area, so line up at least two experienced helpers and have the truck deliver close to the forms. For more on small pours, see the small concrete slab guide.
Planning something bigger? A 20x20 slab covers a two-car garage or a full-size patio. For a smaller shed or hot tub pad, see the 12x12 slab cost.