Walk the site before you run the math
Concrete estimates live or die on site conditions. Walk the area and note what the pour actually involves: slope and drainage, soil condition, existing concrete to remove, tree roots, and how the truck gets to the forms. A backyard patio with no wheelbarrow access is a different job than a driveway off the street, even at identical yardage.
Check thickness requirements with the customer and the intended use, and check local requirements for permits or inspections before you price. Measure the area yourself rather than trusting the customer's dimensions, and sketch the shape so odd angles and curves get measured instead of guessed.
Access decides cost. If the truck cannot reach the forms, you are paying for a pump, a buggy, or a lot of wheelbarrow hours. Price the access, not just the concrete.
Calculate cubic yards
Concrete is ordered by the cubic yard, and the math is simple: length times width times depth, all in feet, divided by 27. Since depth is usually given in inches, convert it first by dividing inches by 12. A 20-by-20-foot slab at 4 inches deep is 20 times 20 times 0.33, about 133 cubic feet, which is roughly 5 cubic yards.
For footings, curbs, and thickened edges, run the same calculation per section and add them together. Then add a realistic overage so the crew never finishes a pour short, because a second truck for a partial yard costs far more than the extra concrete would have. Round to what your supplier actually delivers.
Count forms, base, and reinforcement
Yardage is only the material in the truck. The estimate also has to carry everything that shapes, supports, and strengthens the pour, and these items scale with the job's geometry rather than its volume.
- Forms and form lumber by linear foot of perimeter, plus stakes and bracing
- Excavation and grading, by the area and depth the site needs
- Gravel or crushed-stone base, by the square footage and compacted depth
- Rebar by the grid layout, or welded wire mesh by the sheet
- Vapor barrier under slabs where specified
- Control joints, expansion material, and curing supplies
- Removal and disposal of existing concrete, by the load
Price the labor and the finish
Concrete labor breaks into phases, and each phase prices differently. Forming and base prep are measured against linear feet and square feet. Pour day is measured against crew size and yardage, because a bigger pour needs more hands for the same hours. Finishing depends on what the customer specified: a broom finish is fast, while stamped, exposed aggregate, or a hard-troweled surface takes skilled hours you must price separately.
Use your own records for how fast your crew forms, pours, and finishes, and multiply hours by your loaded crew cost. Materials go in at supplier cost including delivery fees and any pump rental. Your markup for overhead and profit goes on top; if you have never built yours from your actual costs, our guide on how to price contractor jobs covers the method.
| Line item | How you size it |
|---|---|
| Concrete | Cubic yards from L x W x D divided by 27, plus overage |
| Forms | Linear feet of perimeter and edges |
| Base and excavation | Square footage times depth |
| Reinforcement | Rebar grid or mesh sheets for the area |
| Labor | Crew hours per phase times loaded hourly cost |
| Finish | Specified finish type times your finishing rate |
| Overhead and profit | Your markup on top of real costs |
Mistakes that sink a concrete bid
- Quoting yardage without walking the access, then paying for a pump out of margin
- Ordering with no overage and finishing the pour short
- Forgetting thickened edges and footings in the volume math
- Leaving excavation and base prep out because the ground looked fine from the truck
- Pricing a basic broom finish when the customer expects stamped or colored concrete
- Not stating what happens if weather delays the pour or soil turns out worse than expected
What belongs on the estimate
A customer-facing concrete estimate should state the slab dimensions and thickness, the mix or strength specified, the reinforcement, the finish, and what site prep is included. Put exclusions in writing, like unsuitable soil, utility relocation, or sealing after cure, and give the price a validity window since material costs move. The format follows the fundamentals in our guide on how to write an estimate.
EstimateBook can draft the estimate while you are still on site: describe the pour by voice or attach photos, and it builds itemized line items you can edit for quantities, prices, and markup before sharing a PDF. Treat the draft as a starting point and verify the yardage math and scope against your own measurements before it reaches the customer.