Concrete Slab Cost Calculator

How to use the concrete slab cost calculator

1. Measure the finished slab — length and width in feet. Add leftover shapes (a stoop, a thickened edge) as extra square feet.
2. Pick the finish. Plain or broom is the everyday gray pad under a shed, patio or garage. Decorative covers stamped or similarly finished work.
3. Pick the thickness. The guides price a 4 inch slab. At 5, 6 or 8 inches the extra concrete is added as its own line at the median ready-mix price.
4. Switch on tear-out or a rebar grid only if they are not already in the quote you are checking.

You get a typical total, a low-to-high range, the all-in price per square foot and the cubic yards in the slab. Type a bid into “Your quote” to see where it lands.

How the estimate is built

Area is length × width, plus any extra square feet. The typical installed rate for a 4 inch slab is the median of the four guides’ central prices. Low and high are the lowest and highest of those central values, not the outer ends of every published range.

• HomeGuide (Feb 3, 2026): $6–$8 per sq ft for a 4 inch slab (center $7).
• Angi (Oct 27, 2026): $4–$8 (center $6). Angi and HomeAdvisor share a data set, so they are counted once.
• Concrete Network (Jul 14, 2026): $6.50–$10.50 for a plain slab (center $8.50).
• Homewyse (May 2026): $10.33–$12.65 on a 129 sq ft model that still excludes excavation and base (center $11.49).

The median of $7, $6, $8.50 and $11.49 is $7.75 per sq ft, with a spread of $6.00–$11.49. Decorative / stamped work uses HomeGuide $8–$19, Angi $10–$18 and Concrete Network $10–$20, a median of $14 per sq ft.

Extra thickness is (inches − 4) × area ÷ 324 cubic yards, priced at the median of five ready-mix figures, $145 per yd³ (the four driveway-guide prices plus Concrete Network’s 2025 national average of $179.95). Ten percent is added to the order quantity, rounded up to the next quarter yard — the same rule as the multi-shape concrete calculator.

A worked example: 20 × 20 ft, 4 inch plain pad

A 20 × 20 ft shed or garage pad is 400 sq ft. At the $7.75 typical rate the installed cost is $3,100, with a published-price spread of $2,400–$4,596. The slab itself contains 400 × 4 ÷ 12 ÷ 27 = 4.94 cubic yards; with a 10% extra the order is 5.50 yd³.

The same pad at 6 inches adds 2.47 yd³ of extra concrete, about $358 at $145 per yard, for a typical total near $3,458. A stamped 10 × 10 ft patio pad at $14 per sq ft is $1,400 before extras. For a driveway with broom, exposed-aggregate or color finishes, use the driveway cost calculator — those finishes are priced from a different set of guides. A thin self-leveling underlayment takeoff — not a structural slab — is on the self-leveling concrete calculator.

What this estimate does not include

A house foundation (Fixr’s slab-on-grade $4–$14, HomeGuide $6–$14, Angi $12–$18 per sq ft) is a different scope: footings, soil, a vapor barrier and often a thicker edge. Regional labor can run 15% below to 35% above these national figures. Fiber-mesh add-ons appear in Angi at $2–$3 per sq ft, but only one guide publishes that increment, so it is not averaged into the typical total. Confirm drainage, permits and access with a local contractor.

Sources & assumptions

How this calculator gets its numbers. Full method: our methodology.

• Typical 4 in plain-slab price is the median of four guides’ central values ($7.75/sf). Low and high are the lowest and highest of those values ($6.00–$11.49).
• Decorative / stamped uses the median of three guides ($14/sf).
• Thicker slabs add only the extra concrete, (inches − 4) × area ÷ 324 yd³, at the $145 median of five ready-mix figures. Extra labor is not added.
• Tear-out typical $4.00/sf and rebar typical $1.125/sf are medians of three guides each (HomeGuide slab or driveway pages, Angi patio removal or slab rebar, and ConcreteCalculate driveway removal/rebar).
• Ready-mix $145/yd is the median of five figures: four from the driveway-guide set (HomeGuide Concrete Prices, HomeAdvisor, ConcreteCalculate, Bob Vila) plus Concrete Network’s 2025 national average.
• Concrete to order = volume plus 10%, rounded up to a quarter yard.
• National estimates; Angi shares HomeAdvisor’s data and is counted once. A house foundation is out of scope.

Sources

1. HomeGuide, Concrete Slab Cost. Feb 3, 2026: 4 in $6–$8/sf; overall $6–$12; stamped $8–$19; removal $3–$8/sf.
2. Angi, How Much Does a Concrete Slab Cost? Oct 27, 2026: $4–$8/sf; rebar +$0.50–$1; fiber +$2–$3; stamped $10–$18/sf.
3. Concrete Network, Concrete Prices. Jul 14, 2026: plain slab $6.50–$10.50/sf; stamped $10–$20; ready-mix $160–$195/yd, 2025 avg $179.95.
4. Homewyse, Cost to Install a Cement Slab. May 2026: $10.33–$12.65/sf on a 129 sf model; excludes excavation and base.
5. Angi, How Much Does It Cost to Install a Patio? Sep 23, 2026: removal $2–$6/sf, used in the slab tear-out median.
6. ConcreteCalculate, How Much Does a Concrete Driveway Cost? 2026 Price Guide. June 9, 2026: removal $1.50–$2.50/sf; rebar $0.75–$1.50/sf; ready-mix $125–$175/yd.
7. HomeGuide, How much does a concrete driveway cost? June 3, 2025: rebar $1–$3/sf, used in the slab rebar median.
8. HomeGuide, Concrete Prices. Jan 6, 2026: delivered ready-mix $119–$147/yd, used in the five-source ready-mix median.
9. HomeAdvisor, How Much Does a Concrete Driveway Cost in 2026? Jun 20, 2026: all-purpose mix $120–$170/yd, used in the ready-mix median. Same data as Angi, counted once.
10. Bob Vila, How Much Does a Concrete Driveway Cost? Apr 15, 2024: ready-mix $125–$150/yd, used in the ready-mix median.

Last reviewed November 12, 2026. Installed prices vary by region, contractor and job conditions; a written local bid wins.