How to Estimate Concrete and Flatwork Jobs
Concrete estimating comes down to accurate volume calculations, knowing your pour conditions, and pricing labor for what the job actually requires — not what it looks like from the truck. Here's how to estimate concrete and flatwork jobs so you make money on every pour.
Step 1: Calculate Cubic Yards
Concrete is priced and ordered by the cubic yard. The formula:
Length (ft) × Width (ft) × Thickness (ft) ÷ 27 = Cubic yards
Convert thickness to feet: 4 inches = 0.333 ft, 6 inches = 0.5 ft
Example — 20×30 ft driveway at 4" thick: 20 × 30 × 0.333 ÷ 27 = 7.4 cubic yards
Always add 5–10% for waste and overage — concrete that falls short mid-pour is a disaster. Round up to the nearest quarter yard.
Common Flatwork Thicknesses
| Application | Typical Thickness |
|---|---|
| Sidewalk / walkway | 4" |
| Residential driveway | 4–5" |
| Driveway with heavy vehicles | 5–6" |
| Patio | 4" |
| Garage floor | 4–5" |
| Commercial slab | 5–6" |
| Equipment pad | 6"+ |
Step 2: Identify Everything That Affects Labor
The slab dimensions are just the start. Walk the job and note:
- Excavation needed? How deep? Rocky soil or clean dig?
- Existing concrete to remove? Demo adds significant time and disposal cost
- Base preparation — gravel base depth, compaction required?
- Forming — straight forms or curved? Single pour or multiple sections?
- Reinforcement — rebar grid, wire mesh, or fiber-reinforced concrete?
- Access for the truck — can the chute reach, or do you need a pump?
- Finishing — broom finish, smooth trowel, exposed aggregate, stamped?
- Control joints — hand-tooled or saw-cut? How many?
- Curing — curing compound, blankets, or wet cure?
A 500 sq ft patio with a straight pour and broom finish is a half-day job. The same 500 sq ft with demo, a curved form, stamped finish, and a pump truck is a 2-day job. Know the difference before you price it.
Step 3: Price the Concrete
Ready-mix concrete pricing varies by region and mix design:
| Mix | Price Range (per yard, delivered) |
|---|---|
| Standard 3,000 PSI | $150–$200 |
| 4,000 PSI (driveways, commercial) | $165–$215 |
| Fiber-reinforced | Add $10–$20/yard |
| Color/pigment | Add $20–$60/yard |
| Short load fee (<5 yards) | $100–$250 flat |
| Saturday/weekend delivery | Add $50–$100 |
| Pump truck (if needed) | $650–$1,200 |
Always call your local batch plant for current pricing — concrete prices fluctuate with fuel and cement costs.
Step 4: Estimate Labor
Typical production rates for a 2–3 person flatwork crew:
| Task | Rate |
|---|---|
| Excavation (manual, 4") | 100–150 sq ft/hr |
| Gravel base, compact | 200–300 sq ft/hr |
| Set forms (straight) | 50–75 lin ft/hr |
| Set forms (curved) | 20–35 lin ft/hr |
| Place mesh/rebar | 200–300 sq ft/hr |
| Pour and screed | 400–600 sq ft/hr |
| Broom finish | 500–700 sq ft/hr |
| Trowel finish | 300–500 sq ft/hr |
| Stamped finish | 100–200 sq ft/hr |
| Saw cut control joints | 100–150 lin ft/hr |
| Strip forms | 75–100 lin ft/hr |
Concrete labor rate: $55–$90/hr per worker depending on skill and market
Sample Estimate: 20×30 Concrete Driveway
Scope: Remove existing asphalt (600 sq ft), excavate 6", install 4" gravel base, pour 4" 4,000 PSI concrete, broom finish, saw-cut control joints.
| Line Item | Qty | Unit | Rate | Total |
|---|---|---|---|---|
| Asphalt demo and haul | 600 | sq ft | $1.25 | $750 |
| Excavation — 6" deep | 600 | sq ft | $0.65 | $390 |
| Gravel base — 4" compacted | 600 | sq ft | $0.85 | $510 |
| Concrete — 4,000 PSI, 8 yards | 8 | yard | $185 | $1,480 |
| Wire mesh (6×6 W1.4) | 600 | sq ft | $0.35 | $210 |
| Form work | 100 | lin ft | $3.50 | $350 |
| Pour, screed, finish — broom | 600 | sq ft | $1.20 | $720 |
| Saw-cut control joints | 80 | lin ft | $2.00 | $160 |
| Curing compound | 600 | sq ft | $0.15 | $90 |
| Permit | 1 | job | $200 | $200 |
| Labor — crew (20 hrs @ $75) | 20 | hr | $75 | $1,500 |
| Subtotal | $6,360 | |||
| Overhead & profit (18%) | $1,145 | |||
| Total | $7,505 |
Sample Estimate: 400 sq ft Stamped Patio
| Line Item | Qty | Unit | Rate | Total |
|---|---|---|---|---|
| Excavation — 4" | 400 | sq ft | $0.65 | $260 |
| Gravel base | 400 | sq ft | $0.75 | $300 |
| Concrete — colored, 4.5 yards | 4.5 | yard | $230 | $1,035 |
| Form work (irregular shape) | 80 | lin ft | $5.00 | $400 |
| Rebar grid (3" spacing) | 400 | sq ft | $0.85 | $340 |
| Stamp, color hardener, release | 400 | sq ft | $2.50 | $1,000 |
| Sealer (2 coats) | 400 | sq ft | $0.65 | $260 |
| Labor — crew (24 hrs @ $75) | 24 | hr | $75 | $1,800 |
| Subtotal | $5,395 | |||
| Overhead & profit (20%) | $1,079 | |||
| Total | $6,474 |
What Kills Concrete Profit
Getting the yardage wrong. Short a yard mid-pour and you're scrambling. Overorder by 2 yards and you're eating $370. Measure accurately and add 8% waste.
Underpricing demo. Breaking out old concrete is hard, slow work. Price it as a real line item with haul-off.
Not pricing pump truck when needed. If the chute won't reach, you need a pump. Get that quote before you submit your bid.
Stamped and colored work without premium pricing. Stamped concrete requires more skill, more time, and expensive materials. Price it at 2–2.5× plain flatwork rates.
Weather dependency. Concrete can't be poured below 40°F or above 90°F without special measures. Include a weather delay clause in your contract.
Bid.Fast lets concrete contractors record a voice walkthrough — dimensions, base conditions, finish type, any special equipment — and generates a complete itemized estimate in 90 seconds.
Try 3 free concrete estimates →
Bid.Fast is a voice-to-estimate app built for concrete and flatwork contractors. Start free →