How to Estimate Concrete Work in 8 Steps

Why concrete bids lose money before the truck arrives

Concrete is unforgiving. It is ordered in bulk and placed once, so you cannot send half a truck back. Order short and you get a cold joint or a second short-load charge. Order long and you pay for the wash-out.

The cubic-yard number is the easy part. The base, the steel, the forms, the finish labor, and the delivery surcharges decide the margin, and those are the lines a rushed estimate drops. The Bureau of Labor Statistics puts the median wage for cement masons and concrete finishers at $27.41 an hour as of May 2025. Ready-mix sells by volume under National Ready Mixed Concrete Association guidance.

How to estimate concrete work in 8 steps

1. Run the cubic-yard math

   Ready-mix is billed by volume, so start there. Multiply length times width times thickness, all in feet, then divide by 27. Convert thickness first, using the decimals in the table below. That is one multiplication you can do standing on the site.

2. Add the waste allowance

   The National Ready Mixed Concrete Association tells purchasers to order 4 to 10 percent more concrete than the plan-dimension estimate. Sit high in that band on small pours and rough subgrade, then round up to the nearest quarter yard.

3. Spec the mix

   The plant prices by strength and additives. Code sets the floor at 2,500 PSI for interior slabs and 3,500 PSI for garage slabs and steps in severe weathering regions, but the practical band runs 3,500 to 5,000 PSI. Name the slump, 3 to 5 inches on most work, and air entrainment at 5 to 7 percent where it freezes.

4. Take off steel, forms, and base

   Concrete is only part of the material cost. Price the wire mesh or tied rebar grid, plus tie wire and chairs, and the form lumber and stakes by the linear foot. Then the base: code calls for a 4-inch compacted course of sand, gravel, or crushed stone under a slab below grade.

5. Scope the finish and the joints

   Two slabs of the same volume can carry very different labor. Broom is the residential default. Stamped and colored multiplies it, adding release powder, mats, color hardener, and a sealer coat. Joint spacing runs 24 to 36 times the slab thickness, about 10 feet on a 4-inch slab, capped at 15 feet.

6. Price the delivery realities

   Plants bill for things volume does not cover. A truck mixer holds 8 to 12 cubic yards, so a small patio pour trips the short-load surcharge. A backyard slab needs a pump with its own minimum. Under ASTM C94 the producer is responsible for the specified slump for 30 minutes, starting when the truck arrives or at the requested delivery time, whichever is later. Ask your plant what its free unloading allowance is and what it bills past it.

7. Load the crew rate

   Price the business, not the paycheck. The median wage for cement masons and concrete finishers is $27.41 an hour as of May 2025, with the 90th percentile at $41.10. Your billed rate has to clear that once payroll taxes, workers comp, liability, vehicle, and tools ride on top.

8. Price the cure, the seal, and the margin

   Curing runs 3 to 7 days with the slab held above 50 degrees Fahrenheit, so carry the compound, the blankets or sheeting, and the return trip to seal. Then stack overhead and profit on the whole direct cost.

Put all eight lines on one branded quote before you leave the driveway →

Slab thickness in decimal feet

What it costs out on a 20 by 30 driveway

The pad is 20 feet by 30 feet, so 600 square feet at 5 inches, or 0.417 feet. That is 250 cubic feet, and dividing by 27 gives about 9.26 cubic yards. Add 8 percent for waste and you order 10 yards. Then say direct cost lands at 4,000 dollars, overhead at 20 percent, and net margin at 10 percent. Divide 4,000 by 0.70 and the customer sees about 5,715 dollars, a markup of roughly 43 percent. Full breakdown in the cost to pour a concrete driveway guide.