A concrete foundation cost calculator prices the concrete package, the part of a foundation a concrete contractor bids: the footings, the walls and the slab as yards at the supplier's price, the reinforcing by the foot, the forms by the square foot of face, the pump if the truck cannot reach, and the finishing. It leaves out the excavation, the backfill and the drainage, which the foundation cost calculator on this site adds for the general contractor's whole foundation estimate, and it is worked here on the 30 by 40 foot footprint used across this site so the two pages agree. The concrete calculator on this site works each element's yards; the concrete price calculator works the delivered price per yard.
The footings, the walls and the slab as yards
The footing is its length times width times depth over 27: on the 30 by 40 footprint the perimeter is 140 feet, and a footing 2 feet wide and 1 foot deep is 280 cubic feet, about 10.4 yards. The stem wall is the perimeter times its height times its thickness: 140 feet by 4 feet by two thirds of a foot is about 373 cubic feet, 13.8 yards. The slab is the footprint times its thickness: 1,200 square feet at 4 inches is 400 cubic feet, 14.8 yards. Together about 39 yards before waste, 43 with it, and at this site's example price of $150 a yard the concrete alone is about $6,400. The concrete calculator on this site works all three shapes and adds them; the requirements for cast-in-place concrete, linked below, govern the placing.
Rebar and mesh: by the foot and by the sheet
Reinforcing is priced by the linear foot of bar at each size and by the sheet of mesh, and the quantity comes from the drawings: bars running the footing continuously with laps at the stated length, verticals in the wall at the stated spacing, and mesh or bars in the slab on the stated grid. The residential code's foundation chapter, linked below, sets the minimums for a dwelling that the drawings apply. On the worked footprint the footing bars alone are several hundred feet with laps, and the calculator carries them as a line at the yard's price per foot, plus the chairs and ties that hold them.
Forms, the pump and the finishing: the lines beyond the yards
Forms are priced by the square foot of face formed, both faces of a stem wall, one face of a footing where the ground does not serve, and the edge of a slab, plus the labor to set and strip them and the ties and release. A pump is hired by the day or the yard where the truck's chute cannot reach the far wall, and it is the line most often forgotten on a sloped lot. Finishing is by the square foot of slab at the stated finish. Each is a line with its own quantity and rate, and the concrete foundation cost calculator on this site prints them beside the yards so the concrete package is the sum of visible lines.
What the package leaves out, and where it goes
Excavation, the stone under the slab, the backfill, the perimeter drain and the waterproofing are the general contractor's lines around the concrete package, and the foundation cost calculator on this site adds them for the whole foundation estimate. The concrete contractor bids the package; the general contractor carries it as a subcontract against the foundation line and bills the foundation draw when it is in. DrawScheduleWorks Pro keeps the package's lines against the job so the yards on the tickets and the feet of bar on the invoices can be checked against the calculated quantities.
Questions people ask about concrete foundation cost calculator
What does a concrete foundation cost calculator include?
The concrete package: footings, stem walls and slab as yards at the supplier's price, rebar by the foot and mesh by the sheet, forms by the square foot of face, the pump and the finishing. Excavation, stone, backfill and drainage are the general contractor's lines around it.
How many yards does a 30 by 40 foundation take?
About 39 yards before waste on the worked example: 10.4 in a 2 by 1 foot footing around the perimeter, 13.8 in a 4 foot stem wall, 14.8 in a 4 inch slab. With a waste allowance, about 43.
What is the most forgotten line?
The pump, on a lot where the truck's chute cannot reach the far wall. It is hired by the day or the yard and it belongs on the estimate before the truck is ordered.