Concrete is ordered by the cubic yard, but the concrete itself is often a small part of the job. Excavation, base, forms, reinforcement and finishing are where the labor goes. This guide covers patios, slabs and driveways.
The short version. Cubic yards = length × width × thickness in feet ÷ 27. Add waste, then price excavation, base, forms, reinforcement, delivery fees and finishing as separate lines.
1. Figure the cubic yards
Convert the thickness to feet (4 inches = 0.333 ft), multiply by the area, and divide by 27 (cubic feet in a cubic yard). Add about 5% to 10% for uneven subgrade and spillage.
Example (illustrative): a 12 × 16 ft patio, 4 inches thick.
| Step | Math | Result |
|---|---|---|
| Area | 12 × 16 | 192 sq ft |
| Volume | 192 × 0.333 | 64 cu ft |
| Cubic yards | 64 ÷ 27 | 2.37 yd |
| Plus 10% | 2.37 × 1.10 | 2.6 yd — round up to what your supplier sells |
Patios and walkways are often 4 inches thick. Driveways that carry vehicles are commonly thicker — check local code and the loads the slab will see.
2. Excavation and base
- Digging out to the right depth, and hauling away the soil
- Base: compacted gravel under the slab, often several inches. Price the stone and the compaction time.
- Grading so water drains away from buildings
3. Forms and reinforcement
- Forms around the edges, set to grade
- Reinforcement: wire mesh, rebar or fiber, as the job and local code call for
- Expansion joint material where the slab meets a house, garage or existing concrete
4. Delivery fees and placing
- Short-load fees: many ready-mix suppliers charge extra for small orders. Ask your supplier — it can change the price of a small patio a lot.
- Pump truck or wheelbarrows: if the truck can't reach, the concrete has to be pumped or wheeled in.
- Wait time: suppliers may charge if the truck waits too long.
5. Finishing and joints
- Finish: broom, smooth, exposed aggregate or stamped. Decorative finishes take much more labor.
- Control joints: a common rule of thumb spaces them about 2 to 3 times the slab thickness in feet — for a 4-inch slab, roughly every 8 to 12 feet.
- Curing and sealing, and keeping people and cars off it until it's ready
6. Figure the labor hours
Estimate each part, and count every person's time — pour day usually needs extra hands. Typical hours for the 12 × 16 ft patio from above.
| Task | Typical labor hours |
|---|---|
| Excavate and haul away soil | 6 |
| Place and compact base | 4 |
| Build forms | 3 |
| Set reinforcement | 1.5 |
| Place and finish (three people × 3 hours) | 9 |
| Strip forms, cut joints, clean up | 2.5 |
| Total | 26 hours |
Labor cost = total hours × your hourly labor cost. Your hourly labor cost is the wage plus burden — payroll taxes, workers' comp and insurance. For example, a $28 wage plus 25% burden is $35 an hour. If you work alone, use the wage you pay yourself. The free labor rates by state tool shows typical wages for your trade and area.
26 hours × $35 = $910 in labor. Most of the hours happen before the truck arrives.
These are typical hours for a straightforward job with an experienced crew. Specialty and custom design work adds hours — for example stamped, colored or exposed-aggregate finishes, curves, steps, and integrated borders. Price those as their own lines, so the customer sees what the extra work costs. Your own times are the best guide: write down how long each task takes on every job, and your estimates get sharper each time.
7. Add overhead and profit
Add materials, labor and fees, then apply your overhead and profit. The free markup and margin calculator does the math.
Tip: Weather can push a pour back. Put on the proposal how a rain delay is handled, so a rescheduled pour doesn't turn into a dispute.
See also: Trades HQ for concrete contractors and Estimating Basics.