Yards are the easy part
Every concrete estimate starts with cubic yards, and anyone who's priced a few knows yards are the least interesting number on the sheet. The ready-mix is a phone call and a price. What decides whether the job makes money is how long it takes to form, how many finishers you need for how many hours, and whether you ordered enough that the truck doesn't leave you half a yard short with the slab half poured.
Here's a method that puts the yards where they belong: first, and then out of the way.
Step 1: Volume, then waste
Length × width × thickness, all in feet, divided by 27, gives cubic yards. A 20 by 40 foot driveway at 4 inches is 20 × 40 × 0.333 = 266.7 cubic feet, or 9.9 yards.
Now add waste. The subgrade is never perfectly to grade, forms bow a little, and the last wheelbarrow always ends up somewhere. As a rule of thumb, 5 percent is the floor for flatwork on a good base, and 10 percent is more realistic on residential work where you didn't prep the base yourself. Thickened edges, footings under the slab and the extra depth at a curb all add volume the plan view doesn't show. Figure them separately and add them in.
Round up to the half yard, because that's how the plant sells it, and check for a short-load fee if you're under their minimum.
Step 2: Forming is where the labor lives
Forming is priced by the linear foot of form, not the square foot of slab. Two slabs with the same area can have very different perimeters. A 20 by 40 rectangle has 120 feet of form. A driveway with a turnaround, a flared apron and a walk to the door might have 200 feet, plus curves.
Count the linear feet. Then figure the labor: straight runs go fast, curves and radius work go slow, and anything against an existing structure takes time to fit. Add stakes and form lumber (or the cost of your reusable forms), form release, and stripping and cleaning.
Step 3: Base and reinforcement
If you're placing on someone else's base, look at it before you price it. If you're building it, price the digging, the stone and the compaction as their own lines.
A common rule of thumb is 4 inches of compacted stone under a residential slab, and more under a commercial drive or a dumpster pad. Figure the stone from area × depth. For the 20 by 40 driveway, 4 inches of base is 266.7 cubic feet, or about 10 cubic yards. Compacted crushed stone runs around 2 tons per cubic yard, so that's roughly 20 tons before waste. Ask your quarry for their number.
Then the reinforcement: wire mesh or rebar, a vapor barrier if the spec calls for one, and fiber if it's in the mix. These are cheap per square foot and easy to forget. Rebar on chairs takes labor to tie. Mesh takes labor to pull up during the pour, and everyone knows how well that goes.
Step 4: The pour and the finish
The pour is a crew for a window of hours that depends on yards, access and weather. Count the people. A residential driveway might be four people for a morning. A commercial slab is more people and probably a pump.
Finishing is the skill you're actually selling, and it's the line estimators most often underprice. A broom finish is the baseline. Exposed aggregate, stamped, colored or hard-troweled work each add hours and material, and stamped work adds the release agent, the stamps and a sealer.
Control joints get tooled or saw-cut, and saw-cutting is a separate trip with a separate tool. A common guideline for joint spacing in feet is two to three times the slab thickness in inches, so a 4-inch slab gets joints every 8 to 12 feet.
Then the finish-out: stripping forms, backfilling the edges, cleanup, and curing compound or a wet cure. Put a number on it.
Step 5: Curb, walks and the small stuff
Curb is priced by the linear foot, with the profile (barrier, rolled or mountable) driving the form cost and the yards. A curb machine changes the math entirely if you own one. Sidewalk is flatwork with a lot of edge and a lot of joints, so price it by the square foot with the perimeter in mind.
Pads for AC units, dumpster enclosures and generators are small, with a high fixed cost: a truck, a crew and half a day, whether it's two yards or eight. Use a minimum charge.
Step 6: Pump, weather and access
If the truck can't get within chute distance, you're pumping or wheeling. A pump is a real cost and a scheduling constraint. Wheelbarrows are labor. Either way, look at the site before you price the pour.
Weather is the concrete-specific risk. Hot days mean retarder and a faster crew. Cold days mean accelerator, blankets and a real chance you don't pour at all. Build a weather allowance into commercial work, and put the weather-delay terms on residential proposals.
Putting it together
For the 20 by 40 driveway:
- Ready-mix: 9.9 yards + 10 percent = 10.9, ordered as 11 yards at the plant price, plus delivery and any short-load fee
- Base: 4 inches of stone, about 20 tons, delivered, placed and compacted
- Forming: 120 linear feet of straight form, plus stakes and lumber
- Reinforcement: mesh or rebar for 800 square feet
- Pour and finish: crew hours, broom finish, tooled joints
- Finish-out: strip, backfill, cure, clean up
- Overhead and margin
That gets you a total, and dividing by 800 square feet gives a per-foot number you can compare with your history. If it's way under what you usually charge, you missed something. Go back and find it.
What to write on the proposal
Put the thickness, mix strength, reinforcement, finish, joint spacing and exclusions on the proposal. Where slabs freeze and see deicing salt, specify air-entrained concrete with a lower water-cement ratio, and let the local code or the engineer's spec set the minimum strength.
Concrete disputes almost always come down to something that wasn't written. The customer expected a smoother finish, thought the walk to the side door was included, or didn't know the apron would be a separate pour. Write it down, and get the signature before the forms go in.
Where Pavr fits
Pavr is job management software for paving, sealcoating, striping and concrete contractors. Its built-in concrete services cover sidewalks, 4-, 6- and 8-inch slabs, curb and gutter, ADA ramps, driveway approaches, patches and saw cuts. Measure the pour on the satellite view or the PDF plan, add your ready-mix price and crew rates, and see the margin before you send it.
If the lot also has asphalt or striping, it all goes on one proposal and one invoice, and each crew sees its own part of the job. The schedule flags a pour when the forecast drops under 40°F. See how one job across trades works.
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