Concrete slab cost calculator

What a concrete estimator does

A concrete estimator turns a slab's dimensions into a dollar figure: how many cubic yards you will order and what the ready-mix, waste, and pump add up to. It answers the pricing question, not the quantity question. The quantities (cubic yards and bag counts for every shape, from slabs to footings to columns) live on the concrete calculator. This page takes those yards and prices them at a ready-mix rate you control. Use the calculator to get the volume, use this estimator to plan the spend.

The cost formula

Volume comes first: cubic yards = length (ft) x width (ft) x (thickness in inches / 12) / 27, because a cubic yard is 27 cubic feet. Then you add waste and price the result. Worked example, a 20 x 20 slab at 4 inches: 400 square feet x 0.333 ft = 133.3 cubic feet, / 27 = 4.94 CY. Add 5 percent waste and you order 5.19 CY. At $165 per cubic yard that is about $855.56 of ready-mix, which works out to $2.14 per square foot. That per-SF figure is material only. It does not include the crew, forms, finishing, or a pump.

How does a concrete footing cost calculator price the pour?

A concrete footing cost calculator treats a continuous footing as a long rectangular pour: cubic yards = linear feet x width in feet x depth in feet / 27. For 27 linear feet at 2 feet wide and 1 foot deep, 27 x 2 x 1 / 27 = 2.00 CY. With 5 percent waste, 2.00 x 1.05 = 2.10 CY; at a planning rate of $165 per cubic yard, 2.10 x $165 = $346.50 of ready-mix. Footing pours are often under roughly 4 cubic yards, so the supplier's short-load fee frequently applies and belongs beside the material line. Use the concrete calculator for footing quantity, then carry the reviewed yards into this estimator at the same delivered rate. You can also price a continuous footing in the calculator above by entering the linear feet as length and the depth in inches as thickness: 27 feet at 2 feet wide and 12 inches deep returns 2.1 CY and $346.50 at $165 per cubic yard.

Ready-mix pricing and short-load fees

Ready-mix runs roughly $150 to $180 per cubic yard delivered, and that range is a planning figure, not a quote: it swings with your market, the mix design (PSI strength, fiber, air entrainment), and fuel. Always price against a real supplier number when you have one. The other line that surprises people is the short-load fee. Plants load a full truck at about 10 CY, and when your pour is under roughly 4 CY they add a per-yard short-load charge to cover the trip. A small stoop or pad can carry a fee that rivals the concrete itself, so on tiny pours confirm minimum-load terms before you book.

What is concrete cost per square foot?

Suppliers sell concrete by the cubic yard, so concrete cost per square foot is a derived figure, not a separate supplier price. For 1 square foot at 4 inches, 1 x 1 x (4 / 12) / 27 = 0.01235 CY; with 5 percent waste, 1 x 1 x (4 / 12) / 27 x 1.05 = 0.01296 CY per square foot. At 4 inches with 5 percent waste, the planning range works out to $1.94 per square foot at $150 per CY and $2.33 per square foot at $180 per CY. That range is a planning figure, not a quote. Use the estimator's length, width, thickness, waste, and ready-mix rate to replace those assumptions with the slab you are pricing.

When you need a concrete pump

A pump is about access, not volume. If the truck chute cannot reach the forms (a backyard slab behind a house, an elevated deck, a long carry over soft ground, or anything the mixer cannot back up to) you rent a pump. A pump day is a flat mobilization cost, typically $900 to $1,200, and it does not scale with the yardage, which is why this estimator keeps it out of the per-square-foot rate. Line-pump versus boom-pump and travel distance move the number, so treat the default as a placeholder and drop in your local rate.

Slab thickness and related figures

Thickness drives both volume and cost, so it is the first number to get right. Four inches is the standard for patios, walkways, and residential floors. Driveways and anything carrying vehicle loads go to 5 or 6 inches, and heavy equipment or thickened edges go deeper still. Every extra inch on a 400 SF slab is another 1.2 CY of concrete, so thickness is not a rounding decision. Waste of 5 percent covers a clean, well-formed pour on flat subgrade; bump it to 10 percent for rough grade, spillage, or complex forms where over-excavation and edge loss eat into the order.

What changes in a concrete floor cost calculator?

A concrete floor cost calculator uses the same length, width, thickness, waste, and ready-mix rate as an exterior slab. Four inches is standard for a residential floor, the same standard thickness as patios and walkways. An exterior slab under vehicle loads moves to 5 or 6 inches, so that load condition changes the volume before the rate is applied. Access is the other check. If the truck chute cannot reach the forms, whether the slab is inside or outside, turn on the pump and enter the local flat day cost. The estimator keeps that pump line separate from material cost per square foot.

Concrete estimator cost: what the number has to include

Estimating concrete cost starts after the order quantity is established. Bring the cubic-yard quantity, including the reviewed waste allowance, from the concrete calculator, then price that quantity with current project inputs. This page is the cost check. The linked calculator owns the volume takeoff.

The delivered cubic-yard price is only the ready-mix line. A defensible estimate also accounts for the work and conditions required to place and finish the concrete:

• Ready-mix: Get a current supplier quote for the specified mix design and the planned order quantity. Confirm what the delivered unit price includes and whether fuel, environmental, seasonal, or other quoted charges sit outside it.
• Mix design and admixtures: Strength, aggregate requirements, air entrainment, fibers, accelerators, retarders, water reducers, color, and other project requirements can change the quoted unit price. Send the supplier the actual schedule and specification instead of pricing a generic mix.
• Short-load fees: Ask the supplier for its current minimum-load terms and charges. The threshold and fee structure vary by plant, so carry the quoted fee as its own line when the order falls below the supplier's minimum.
• Placement labor: Build the crew cost from the contractor's production history and loaded labor rates for the actual placement. Access, reinforcement congestion, slab geometry, discharge method, weather plan, and pour sequence all affect the hours.
• Pump or crane time: When the truck cannot discharge where the concrete is placed, obtain a project quote for the selected equipment. Check mobilization, minimum time, travel, hose or boom requirements, setup area, washout, standby, and overtime terms instead of carrying an unsupported flat allowance.
• Finishing: Price the specified finish and tolerance with the crew and equipment it requires. Screeding, floating, troweling, broom finish, edges, joints, curing, and special surface requirements should be visible when they are in scope.

Source the number in the order it will be spent. First, confirm the mix and order quantity with the drawings and specifications. Next, request supplier quotes using the same delivery location, pour conditions, mix, quantity, and included charges. Then normalize the quotes so one supplier's bundled delivery charge is not compared with another supplier's base plant rate.

Build the estimate as separate, checkable lines:

1. Ready-mix cost = reviewed order quantity x current delivered price per cubic yard.
2. Add supplier charges confirmed for that order, including any applicable short-load line.
3. Add placement labor from reviewed crew hours and loaded rates.
4. Add quoted pump or crane time when access requires it.
5. Add finishing labor, finishing equipment, curing, testing, and other concrete scope included in the bid.
6. Divide the relevant total by the slab area only when a cost-per-square-foot comparison is useful, and label what that rate includes.

The calculator on this page gives the ready-mix material cost, an optional pump line, the combined total, and ready-mix material cost per square foot of slab. It does not become a full placed-concrete estimate until the estimator carries placement labor, finishing, supplier fees, and the rest of the included scope. Keep those lines visible so a reviewer can trace every cost to a quote, a company rate, or a stated estimating assumption.

From cubic yards to a priced bid

A slab total is one number on a job that has many. The full estimate has to fold in rebar or mesh, vapor barrier, forms, the finishing crew, and every other assembly on the drawings, and that takeoff is where bids are won or lost. Ruh reads your plan set, quantifies the concrete and everything around it, and drafts a priced estimate against your own cost book, so the ready-mix line is traceable back to the sheet it came from. See how it works on the concrete estimating software page.