How to Estimate a Concrete Driveway | Reddit & LinkedIn

Start with square footage: length times width. Then convert slab thickness to feet, four inches is 0.333 feet, and multiply. Divide the result by 27 to get cubic yards, since a yard of concrete is 27 cubic feet. Add about 10% for waste, spillage, and subgrade that is not perfectly level.

Getting volume right is the foundation of the whole estimate. Order short and you pay for a second small delivery at a premium. Order long and you paid for concrete that went in the wash rack. On a typical two-car driveway around 600 square feet at four inches, you are near 7.5 to 8 cubic yards once waste is included.

Concrete is the headline, but it is not the whole material bill. You need a compacted gravel base, reinforcement with rebar or welded wire mesh, form lumber or steel forms, form stakes, curing compound, and control-joint materials. Each is its own line so a client can see what they are paying for and you do not absorb a forgotten cost.

Reinforcement choice depends on load. A standard residential drive often uses wire mesh or light rebar, while a drive that will carry an RV or work trucks needs a thicker slab and heavier rebar on a grid. Spelling this out protects you if the client later parks something the original spec never covered.

Split labor into excavation and grading, base compaction, forming, pouring, finishing, and cleanup. Assign hours to each and multiply by your loaded labor rate. Finishing is where skill and time concentrate, especially if the client wants a broom, exposed-aggregate, or stamped surface, so price the finish they actually chose.

Removal of an existing driveway is a common labor and disposal cost that estimators miss. Breaking out and hauling old concrete adds equipment time and dump fees. Walk the site, confirm whether demolition is in scope, and if it is, give it its own line rather than burying it in a vague labor lump.

Two driveways of identical size can price hundreds of dollars apart because of access and soil. If a ready-mix truck can back straight to the forms, the pour is fast. If crews have to wheelbarrow or pump concrete around a house, labor climbs. Poor or expansive subgrade may need extra gravel, a thicker slab, or fabric, all of which add cost.

This is why a real site walk beats a phone quote. Note truck access, slope, drainage, tree roots, and the condition of any slab being replaced. Pricing these upfront keeps you from eating the difference mid-pour and keeps the client from feeling surprised by a change order they did not see coming.

Once you have volume, materials, and labor, apply your markup, usually 18 to 25% on a concrete job, over a loaded labor rate, and add a small contingency for subgrade surprises. Present one itemized, signable estimate that shows the slab spec, the finish, and a payment schedule, and send it the same day when you can.

ContractShield speeds this up. Photograph the site, enter dimensions and the finish, and the AI drafts the material and labor lines from your own templates in about 25 minutes, each line marked as your template or an AI estimate and none of your rates invented. Then it invoices a deposit and a completion draw and chases any overdue balance automatically.