Concrete is one of the few trades where the math is unforgiving — order too few yards and you have a cold joint and a callback; order too many and you paid for concrete sitting in the truck. A bid that shows the cubic-yard calculation, prices forms and rebar separately from the pour, and states the finish reads as competent to a homeowner and gives you a real number to work from, not a per-square-foot guess pulled from a competitor’s flyer.

What every concrete estimate needs

Miss one of these and either the bid looks like a guess or the job eats your margin:

• Client name, job address, and dimensions — square footage and slab thickness, since both drive the cubic-yard math.
• Cubic yards of concrete, calculated from the dimensions and thickness with a waste factor (typically 5–10%) added — not a round number.
• Forms and grading priced separately, since layout and base prep vary more than the pour itself.
• Rebar or wire mesh as its own line, specifying the spacing or gauge used.
• Gravel base where the sub-grade needs it, priced by depth and area.
• Labor for the pour, screed, and finish, based on your real crew size and hours.
• Finish type (broom, exposed aggregate, stamped) and control-joint layout, since finish work is priced differently than the structural pour.
• Markup and a contingency for weather delays or a subgrade that needs extra prep, plus a permit line where your jurisdiction requires one.

A real concrete estimate, line by line (a 600 sq ft driveway)

Here is how a 600 sq ft, 4-inch driveway with rebar reinforcement and a broom finish prices out:

That works out to roughly $10.35 per square foot all-in — a useful sanity check against local competitors, but only after the yardage, forms, rebar, and finish are priced as real line items. A per-square-foot number without the breakdown behind it is a guess wearing a bid’s clothing.

Calculating cubic yards (the math the whole bid rests on)

Cubic yards = (length × width × thickness in feet) ÷ 27. For this driveway: 600 sq ft × 0.33 ft (4 inches) = 198 cubic feet ÷ 27 = 7.3 cubic yards. Add a 5–10% waste factor for spillage, over-excavation, and an uneven subgrade, and round up to the next half or full yard — here, 8 cubic yards. Rounding down to save $175 on paper is how a job runs short mid-pour, which costs far more than the extra yard would have.

Forms, rebar, and finish — why they need separate lines

Forms and grading cost roughly the same whether you pour a driveway or a patio of the same size, since layout and base prep do not scale with cubic yards the way concrete does — price it flat per job, not per yard. Rebar or wire mesh should be its own line naming the spacing or gauge, since a client comparing bids will ask what reinforcement they are getting. Finish (broom, exposed aggregate, stamped, or a decorative border) changes the labor and material cost more than any other variable on the job, so never fold it into a blended per-square-foot rate.

Markup, contingency, and the risk concrete carries that other trades don’t

Most concrete contractors run 12–18% markup to cover overhead and profit. Layer a separate 7–10% contingency — higher than most trades — because a pour is uniquely exposed to weather delays, a subgrade that needs more base than expected, and a delivery truck that shows up with concrete that will not wait. Quote it as its own line so the client understands why concrete bids build in more cushion than a typical remodel quote.

Once the pour is finished and cured, turn the approved bid into payment: send an itemized concrete invoice that mirrors the same yardage, forms, and finish lines the client already signed off on.

Frequently asked questions