Concrete Cost per Square Foot Calculator

How do you work out concrete cost per square foot?

Take the price per cubic yard your ready-mix plant quotes, multiply by the slab thickness in inches and divide by 324. That gives the concrete cost per square foot. Labor, base, reinforcement and delivery fees are separate lines that you add per square foot or as lump sums.

Concrete $/ft² = price per yd³ × thickness (in) ÷ 324

The 324 is not a magic number. One cubic yard is 27 ft³, and 27 ft³ spread 1 in (1/12 ft) thick covers 27 × 12 = 324 ft². At 4 in the same yard covers 324 ÷ 4 = 81 ft², at 6 in only 54 ft².

We do not publish a national average price per square foot. Ready-mix prices, labor rates and fees vary too much by region and season for one figure to help, and we have not found a primary source that publishes one. Instead, this page turns your yard quote into a square-foot price for any thickness, then shows where the rest of a contractor’s square-foot quote comes from. Enter your own numbers in the calculator above: it adds 10% extra, rounds the order up to the next ¼ yd³ and divides the total by the area.

Concrete cost per square foot by thickness: the matrix

Find your thickness in the left column and your yard quote across the top. Each cell is the concrete cost per square foot with 10% extra included, before rounding the order to the next ¼ yd³. The yard prices across the top are example inputs, not market prices; if your quote falls between columns, use the “per $100” column and scale it.

Two patterns are worth noticing. First, the concrete cost per square foot is directly proportional to thickness: going from 4 to 6 in raises it by exactly 50% at any yard price. Second, every $25 change in your yard quote moves a 4 in slab by only about $0.34 per ft² with 10% extra. Shopping plants matters, but on most jobs the labor rate and fees move the square-foot price more.

Where do thicknesses come from? Your plans, your contractor and your local building code set them, not this table. The rows simply cover the thicknesses people usually price: thin overlays and walks, standard 4 in flatwork, 5–6 in driveways and garage floors, and 8 in for heavier use.

How much does concrete cost per square foot for a slab, driveway, patio or sidewalk?

The project type changes the price per square foot mainly through thickness and size. Thicker pours use more concrete per foot, and small pours pay for rounding and minimum-load fees. The table compares common jobs with 10% extra and the order rounded up to the next ¼ yd³, so it shows what you actually pay for.

To read a row at your own price, multiply the last-but-one column by your yard quote ÷ 100. A 12 × 40 ft driveway at 5 in and an example $160/yd³ is 1.6 × $1.72 = $2.75 per ft² of concrete. For house slabs with thickened edges or footings, use slab foundation cost, because the edges add volume that a flat per-foot figure misses.

The sidewalk and patio rows match closely because both are 4 in flatwork of similar area. Sidewalk thickness and width at the street are often set by the city, so check with your public works or permit office before you price one.

Why do small pours cost more per square foot?

Ready-mix is ordered in steps (we use ¼ yd³), and many plants add a fee below their minimum load. Both are fixed amounts, so they weigh more on a small area. A 3 × 3 ft pad at 4 in needs only 0.11 yd³, but the smallest ¼ yd³ step makes the concrete $2.78 per ft² for each $100 of yard price, about double the $1.38 of a 20 × 20 ft slab.

Fees behave the same way. Spread an example $90 small-load fee over the area and it adds:

Fee amounts and minimum loads are set by each plant, so ask for both when you call. For the tiniest pads, bagged concrete avoids the fee: an 80 lb bag of QUIKRETE Concrete Mix yields about 0.60 ft³, so a yard takes 45 bags. The concrete pad cost section on the slab cost page compares bags and ready-mix by pad size.

What else goes into a contractor’s price per square foot?

When a contractor quotes one figure per square foot, the concrete is only one part of it. The rest covers labor and materials that do not depend on your yard price.

• Placing and finishing labor. Usually the largest line on flatwork. Quoted per square foot.
• Excavation and base. Digging out, hauling soil and a compacted gravel base, priced by the ton. The gravel calculator gives tons for a base depth.
• Forms. Lumber and setting time, often more per foot on curved or narrow pours such as sidewalks.
• Reinforcement. Rebar, wire mesh or fiber. The rebar calculator counts bars for a grid.
• Delivery, short-load and waiting fees. Lump sums from the plant; divide by area to see their weight per square foot.
• Access. A pump or power buggies when the truck cannot reach the forms.
• Finish. Broom finish is the baseline. Stamping, color, exposed aggregate and sealer are a separate decorative line priced by the finisher per square foot. The concrete patio cost page shows how to estimate stamped work, including border-only stamping.
• Removal of an old slab. Demolition and haul-away, covered on the driveway cost page.
• Permits and inspections where your jurisdiction requires them.

Worked examples: from yard price to all-in cost per square foot

These examples use made-up inputs so you can follow the arithmetic: a $160/yd³ ready-mix price, a $90 small-load fee and $6/ft² for labor, forms and finishing. Replace each one with your own quotes in the calculator above.

The last example is why “thicker” often costs less than people fear. The concrete grows by 21% from 5 to 6 in on this drive (8¼ to 10 yd³ ordered), but the all-in square-foot price in the example rises from $8.75 to $9.33. Your ratio will depend on how your labor rate compares with your yard price.

How much is concrete per square metre?

In metric, multiply the price per cubic metre by the thickness in metres. A 100 mm slab uses 0.1 m³ per m², so every 100 of your local m³ price adds 10 per m² of concrete, or 11 with 10% extra. Currency does not matter; the arithmetic is the same.

To compare a metric quote with a US one, 1 yd³ = 0.7646 m³ (NIST SP 811), so a price per m³ × 0.7646 gives the price per yd³.

How do I get an accurate price per square foot?

Start from the quantity, then collect three kinds of price.

1. Measure and choose the thickness. Use the concrete slab calculator for the yards, or the calculator above for yards and cost together.
2. Call two or three ready-mix plants. Ask for the price per yard of the mix you need, their minimum load and the fee below it, and the free unloading time. The concrete price per yard page lists the questions to ask.
3. Get itemized contractor quotes for labor, base, forms, reinforcement and finish, each per square foot or as a lump sum.
4. Enter everything above and read the “per square foot” result. Change the thickness to see what an extra inch really costs on your job.
5. Compare per square foot only after checking that every quote covers the same items.

Common mistakes when comparing prices per square foot

• Comparing a concrete-only figure with an all-in quote. The matrix above is concrete only; a contractor’s square-foot price includes labor and more.
• Forgetting thickness. A 4 in patio price per square foot does not apply to a 6 in driveway; the concrete line is 50% higher.
• Using a big-slab rate for a small pad. Rounding and fees can double the concrete cost per square foot on pads under about 10 ft².
• Leaving out waste. Ordering the exact volume risks running short; the calculator adds 10%, which is about $0.12–$0.19 per ft² per $100/yd³ at 4–6 in.
• Copying a price from another region or year. Use quotes from plants and contractors that serve your address, dated this season.