Concrete Slab Cost Estimator
Planning estimate, not a contractor quote. Enter your slab size and local ready-mix price for a materials cost and a realistic all-in range.
Concrete Slab Cost Estimator
About this concrete slab cost estimator
Concrete work has two price tags: materials (the concrete itself, which is simple arithmetic) and everything else (forming, base prep, rebar or mesh, pouring labor, finishing — which is where quotes diverge). This estimator nails the first number from your slab dimensions and local per-yard price, then brackets the second with a typical all-in range.
The all-in range assumes hired labor at normal residential rates: forming and base prep, the pour, and a broomed or troweled finish. It does not include demolition of old concrete, difficult access (pump trucks add hundreds), decorative finishes like stamping, or permits. Complex sites land above the range; simple flat slabs land near the bottom.
Use this number the way contractors use a takeoff: as the starting point for conversations, not the final word. Real quotes reflect your soil, your access, your finish, and your market — three local quotes will teach you more than any calculator.
Worked example: pricing a 20×20 patio slab
A 20×20 ft slab at 4 inches thick: 20 × 20 × (4 ÷ 12) = 133.33 cubic feet, divided by 27 = 4.94 cubic yards. At $150 per cubic yard, concrete materials run about $741. This calculator then builds an all-in planning range around the materials figure: roughly $1,037 on the low end to $1,630 on the high end, covering delivery, gravel base, forming, rebar or mesh, labor, and finishing.
Notice the gap between $741 in concrete and a $1,037–$1,630 all-in cost: the concrete itself is often less than half the project. Labor, forming lumber, base prep, and delivery fees add up fast — which is exactly why a materials-only number misleads DIY budgeters.
Getting a useful number
Concrete prices swing by region and by order size. Small loads (under roughly 3–4 cubic yards) usually trigger a short-load fee from the ready-mix plant, because the truck makes the trip regardless — for under about half a yard, mixing bags yourself is typically cheaper. Call two or three local plants: the per-yard price spread between them is often $20–$40, which is real money on a 5-yard pour.
Beyond the concrete, budget $1–$2 per square foot for the extras on a basic residential slab: gravel base, forming lumber, rebar or wire mesh, and finishing. And remember this is a planning estimate, not a contractor quote — always get local quotes before committing to a budget.
How to use
- Enter your slab length, width (ft), and thickness (in).
- Enter your local ready-mix price per cubic yard (call a plant, or use the $150 default as a rough US figure).
- Press Calculate for materials and the all-in range.
- Get 3 local quotes — treat this as your sanity check on them, not a replacement.
Good to know
- Planning estimate only — never a quote. Prices move with fuel, region, and season.
- Excludes demolition, pump trucks, decorative finishes, and permits.
- Assumes standard 4-inch residential slab; structural or commercial work needs engineering.
- Small loads cost more per yard — most ready-mix plants charge a short-load fee under 3–4 cubic yards, and some have order minimums. Bag mix can be cheaper for tiny pours.
- Rebar or wire mesh, gravel base, and forming lumber are real costs: budget $1–$2 per square foot beyond the concrete itself for a basic residential slab.
Frequently asked questions
How much does it cost to pour a concrete slab?
Materials run roughly $100–$200 per cubic yard of ready-mix depending on region. All-in installed cost for a standard 4-inch residential slab typically lands at $6–$12+ per square foot. A 20×12 slab (~3 cubic yards) often totals $1,500–$3,000+ depending on prep and finish.
What is the cheapest way to pour a small slab?
For under ~1/2 cubic yard, mixing bags yourself is cheapest. Above that, ready-mix or a volumetric (metered) truck wins on cost and labor.
How thick should a concrete slab be?
4 inches for patios, walkways, and light residential use; 6 inches for driveways and anything carrying vehicles. Thicker slabs use proportionally more concrete — the estimator accounts for it.
Why do concrete quotes vary so much?
Access, soil conditions, demolition, finish type, and local labor markets all swing the price. The concrete itself is the most predictable line item — which is what this estimator pins down.
Does this include rebar?
No — rebar or wire mesh, forming lumber, and base gravel are separate line items. Budget roughly 10–20% on top of the concrete materials for them on a simple slab.
How much does a 20x20 concrete slab cost?
A 20×20 ft slab at 4 inches thick is about 4.94 cubic yards. At $150 per yard, materials run roughly $741, with an all-in planning range of about $1,037–$1,630 including labor, base, and forming. Enter your dimensions above for your exact numbers — and always get local quotes, since rates vary widely.
What is included in the all-in cost range?
The range covers concrete, delivery, gravel base, forming, rebar or mesh, labor, and finishing. It does not include excavation of difficult soil, demolition of old concrete, or permit fees — ask your contractor to itemize those separately.
Why is small-pour concrete more expensive per yard?
Plants charge short-load fees for orders under roughly 3–4 yards because the truck still makes the trip. For under about half a cubic yard, mixing 60 lb or 80 lb bags yourself is usually cheaper than calling a truck.
How thick should my concrete slab be?
4 inches for patios and walkways, 5–6 inches for driveways and garage floors. Anything structural — foundations, load-bearing slabs — needs an engineer’s specification, not this estimator.