How to Create a Complete Concrete Estimate: Every Line Item Contractors Need

A concrete bid that misses even one line item can turn a profitable job into a money loser before the first truck rolls in.

Concrete is an unforgiving trade to estimate. You’ve got a narrow window from the time you call for a pour to the time the slab is finished. No redos. No “we’ll fix that tomorrow.” If your estimate is short, you’re eating the difference. If your price is too high, you lose the bid.

After 20 years in the trades, I’ve seen both happen. The contractors who consistently win profitable concrete work aren’t the ones guessing from experience - they’re the ones with a system. Same checklist, every bid, every time.

This guide walks through that system: every cost bucket, how to calculate each one, and worked examples you can use as a reference on your next bid.

Quick Answer: What Goes Into a Concrete Estimate?

A complete concrete estimate has seven cost categories. Most contractors miss at least two of them on early bids, which is exactly why bids come in short.

Site prep and excavation - grading, excavation, gravel sub-base
Forming - lumber, form hardware, snap ties, stripping labor
Reinforcement - rebar or wire mesh, chairs, tie wire
Concrete material - ready-mix by the yard, pump truck if needed
Placement and finishing - pour crew, screeding, troweling, edging, broom finish
Curing and sealing - curing compound or wet cure, sealer if specified
Cleanup and disposal - form lumber disposal, concrete washout, debris removal

Add overhead and profit on top of those seven and you have a complete number. Skip any one of them and you’re cutting your own margin.

Line-by-Line Breakdown: What to Estimate and How

Site Prep and Excavation

Site prep is often the most variable cost on a concrete job. A flat, accessible residential backyard is one thing. A sloped lot with drainage issues and limited truck access is another.

What to account for:

Excavation depth: A 4-inch slab needs at least 4 inches of excavation plus the sub-base. On a 500 sq ft slab with 4 inches of gravel sub-base, you’re moving roughly 33 cubic yards of material.
Gravel sub-base: Standard is 4-6 inches of compacted crushed stone or gravel. At $18-28 per ton delivered and roughly 1.4 tons per cubic yard, budget $25-40 per cubic yard installed.
Compaction: If you’re renting a plate compactor, add that to equipment. If your crew is doing it, add man-hours. Skipping compaction is how slabs crack in the first two years.
Forming area cuts: Edges, corners, and any areas adjacent to structures need clean cuts. Add extra labor time here.

Site prep cost range for a typical residential slab: $0.75 to $2.50 per square foot, depending heavily on site conditions.

Forming

Forms are what give your slab its shape. They also have to hold the pressure of wet concrete - typically around 150 lbs per cubic foot - without blowing out.

Form costs include:

Dimensional lumber (2x4 or 2x6 depending on slab thickness): Calculate the perimeter in linear feet. A 20x24 slab has 88 linear feet of form. At $0.65-0.90 per linear foot for 2x6 lumber, that’s $57-79 in material. Add stakes at roughly $0.50 each, every 18-24 inches.
Snap ties and form hardware for anything taller than a slab: mostly applies to walls and footings, but worth noting if your job includes grade beams.
Form stripping labor: Usually 30-45 minutes per 100 linear feet of perimeter forms.

Budget roughly $0.50 to $1.25 per linear foot for forming material and hardware, plus labor.

Reinforcement

Reinforcement is the skeleton of the slab. It doesn’t stop concrete from cracking - nothing does - but it holds cracks together when they happen and dramatically extends slab life.

Two options:

Reinforcement Type	Material Cost	Installed Cost	Best For
Wire mesh (6x6 W1.4/W1.4)	$0.10-0.20/sq ft	$0.15-0.35/sq ft	Light-duty pads, walkways
#3 rebar at 18” OC	$0.30-0.50/sq ft	$0.50-0.90/sq ft	Residential patios, shed pads
#4 rebar at 12” OC	$0.45-0.75/sq ft	$0.75-1.25/sq ft	Garage floors, driveways
#4 rebar at 12” OC both ways	$0.75-1.00/sq ft	$1.10-1.75/sq ft	Heavy vehicle loading

Wire mesh is faster to install but has a critical weakness: it shifts during the pour and often ends up at the bottom of the slab where it contributes almost nothing. Rebar on chairs stays in position. For anything structural or anything with vehicle traffic, use rebar.

Use the rebar spacing calculator to get the exact bar count and total linear footage for your slab dimensions before you price this line item.

Concrete Material

Concrete is sold by the cubic yard. Get your volume right before you call the batch plant.

The formula: Length (ft) x Width (ft) x Thickness (inches) / 12 / 27 = cubic yards

Then add 5-10% for waste, spillage, and any low spots in your sub-base.

Current ready-mix pricing in 2026:

Market Type	Price Per Cubic Yard
Rural / lower-cost markets	$95-120/yd
Midwest / Mountain West	$110-140/yd
Pacific Northwest, California	$140-165/yd
Northeast corridor	$145-175/yd

Don’t forget pump truck cost if the pour site doesn’t have direct truck access. A concrete pump runs $650-1,200 for a half-day depending on your market, plus operator time. If you’re doing patios on a backyard lot with no truck access, that pump line is not optional.

Use the concrete calculator to work out your exact yardage, and the concrete cost per yard calculator to check current regional pricing before you finalize your number.

Placement and Finishing

This is where labor gets real. The pour window is short - typically 60-90 minutes from discharge - and you need enough hands to place, screed, and begin finishing before the concrete stiffens.

Crew typically needed for a residential slab:

2-3 finishers minimum for anything under 800 sq ft
4-5 for larger pours or anything with tight access
Add 1 person to manage the truck, chute positioning, and form monitoring

Labor rates for concrete finishers (2026):

Basic markets: $28-40/hour
Pacific Northwest, California: $45-65/hour
Union work: $65-90+/hour

Finishing tasks and time estimates per 1,000 sq ft:

Task	Time Estimate
Setting screed guides and pulling screeds	1.5-2.5 hours (2 workers)
Bull floating	0.5-1 hour
Final troweling (power trowel or hand)	2-4 hours depending on finish spec
Broom finishing	0.5-1 hour
Edging and control joint cutting	1-2 hours

Total labor for placement and finishing on a 500 sq ft slab: budget 6-12 man-hours depending on access, shape complexity, and finish specification.

Curing and Sealing

Concrete needs to retain moisture for the first 28 days to reach full strength. In hot, dry, or windy conditions, this is critical. Skipping cure is how you get surface scaling and early cracking.

Curing options:

Curing compound (spray-applied): $0.05-0.15 per sq ft material. Fast and easy. One coat applied immediately after finishing.
Wet cure (burlap or plastic sheeting): $0.10-0.25 per sq ft in labor and material, but more effective in extreme conditions.
Concrete sealer: Often a separate line item requested by homeowners on driveways and patios. Budget $0.20-0.50 per sq ft for material and application labor.

Cleanup and Disposal

This is the most commonly forgotten line item. Concrete is heavy and messy, and proper cleanup takes real time.

Form lumber: Stripping, stacking, and hauling. If it’s reusable, account for cleanup and storage. If it’s disposal, add dumpster or haul-away cost.
Concrete washout: Batch trucks and pumps need a washout area. You’re responsible for having one and disposing of it properly. Many municipalities require a washout containment bag. Budget $50-150 for this.
Final site cleanup: Broom sweep, debris pickup, restoration of any disturbed areas around the slab perimeter.

Budget $150-400 for cleanup on a typical residential job. It’s a real line item, not an afterthought.

Overhead and Profit

Never forget these. They’re not optional add-ons - they’re the cost of running the business and the reason you’re doing the work.

Overhead: 10-15% on labor and materials covers insurance, truck, tools, licensing, office time, and the estimating time you spent on this bid.
Profit: 10-15% minimum for straightforward residential concrete. Higher on tight-access jobs, specialty finishes, or anything with unusual risk.

For more on how to apply markup correctly without confusing it with margin, see the contractor estimate template - it has the math built in.

Worked Example 1: Garage Slab Estimate (20x24 ft, 5 inches)

Project: Detached garage floor in the Pacific Northwest. 20x24 ft, 5 inches thick, #4 rebar at 12” OC, broom finish.

Square footage: 480 sq ft Cubic yards (with 7% waste): 7.8 yards

Line Item	Calculation	Cost
Site prep and gravel base (4 in compacted)	480 sq ft x $1.50/sq ft	$720
Forming (88 LF perimeter, 2x6)	88 LF x $1.00/LF + stakes	$135
Rebar (#4 at 12” OC, installed)	480 sq ft x $1.10/sq ft	$528
Ready-mix concrete (7.8 yds at $148/yd)	7.8 x $148	$1,154
Placement and finishing (10 man-hours at $52/hr)	10 hrs x $52	$520
Curing compound	480 sq ft x $0.10	$48
Cleanup and disposal	Flat allowance	$225
Subtotal		$3,330
Overhead (12%)		$400
Profit (13%)		$433
Total Bid		$4,163

Per square foot: $8.67

That’s a solid, profitable number for a garage floor in a mid-to-high labor market. In a lower-cost market, you might come in at $6.50-7.50. In Seattle or the Bay Area, closer to $10-12.

Worked Example 2: Residential Driveway Estimate (12x40 ft, 5 inches)

Project: Residential driveway replacement in a mid-range market. 12x40 ft, 5 inches thick, #4 rebar at 12” OC, broom finish. No demo (existing was gravel).

Square footage: 480 sq ft Cubic yards (with 7% waste): 7.8 yards

Line Item	Calculation	Cost
Site prep and gravel base (6 in, driveway spec)	480 sq ft x $1.75/sq ft	$840
Forming (104 LF perimeter, 2x6)	104 LF x $0.95/LF + stakes	$155
Rebar (#4 at 12” OC, installed)	480 sq ft x $1.10/sq ft	$528
Ready-mix concrete (7.8 yds at $128/yd)	7.8 x $128	$998
Placement and finishing (10 man-hours at $38/hr)	10 hrs x $38	$380
Control joint cutting (4 joints, 12 LF each)	48 LF x $1.25/LF	$60
Curing compound	480 sq ft x $0.10	$48
Cleanup and disposal	Flat allowance	$200
Subtotal		$3,209
Overhead (12%)		$385
Profit (13%)		$416
Total Bid		$4,010

Per square foot: $8.35

Driveways in mid-range markets tend to land in that $7-10 range for a standard spec job. The variable that moves the number most is labor rate and whether the site has any complications - slope, access, soil conditions.

Common Estimating Mistakes That Cost Contractors Money

Forgetting the pump truck. If the pour site doesn’t have direct truck access, you’re renting a pump. That’s $700-1,200 you didn’t budget. Do a site visit before you bid.

Using old concrete prices. Ready-mix prices have moved significantly over the past few years. Call your batch plant for current pricing before every bid, not before every quarter.

Underestimating finishing labor. Concrete finishing is skilled work. A crew that’s slow on a pour can cost you two or three times what a faster crew saves on hourly rate. Budget for experienced finishers, not whoever’s available.

Missing the washout line. It’s a small cost, but municipalities are getting stricter about concrete washout. Budget it and do it right.

Not adding enough waste factor. Seven percent is standard for residential slabs. Bump it to 10% if the slab has multiple angles, curves, or if your sub-base has any low spots. Running short mid-pour is a bad situation.

Skipping overhead. This is the most common error from contractors new to running the business side. If you don’t charge for overhead, you’re subsidizing your clients out of your own pocket.

Try EstimationPro free

Frequently Asked Questions

How do I calculate how much concrete I need?

Multiply length (ft) x width (ft) x thickness (inches), divide by 12 to get cubic feet, then divide by 27 to get cubic yards. Add 5-10% for waste. For a 20x24 ft slab at 5 inches: (20 x 24 x 5) / 12 / 27 = 7.41 yards. Add 7% waste and order 8 yards. The concrete calculator does this math instantly.

What is the average labor cost for pouring concrete?

Labor for residential concrete runs $2.50-5.00 per square foot in mid-range markets and $5-8 per square foot in high-cost markets like California and the Pacific Northwest. This includes forming, placing, screeding, finishing, and basic curing. It does not include site prep, which is typically bid separately.

How long does it take to pour a concrete slab?

A 500 sq ft garage slab typically takes one full day with a crew of 3-4. That includes arriving, setting up, receiving the truck, placing, screeding, finishing, and cleanup. Larger slabs or more complex finishes extend that timeline. Never try to rush the finishing window - the concrete does not care about your schedule.

What PSI concrete should I specify for residential work?

3,000 PSI is the standard minimum for residential slabs. Specify 3,500 PSI for driveways or anywhere exposed to freeze-thaw cycles and deicing salts. 4,000 PSI for commercial floors or anything with heavy point loads. The mix design also matters - air-entrained concrete is important in cold climates.

Do I need a permit to pour a concrete slab?

In most jurisdictions, yes, for anything attached to a structure or for driveways over a certain size. Detached patio pads in many areas don’t require a permit, but check with your local building department before you bid the job, not after. Finding out mid-project that a permit was required is a bad conversation with the client.

How do I account for rebar in my concrete estimate?

Figure out your slab area, determine your rebar spacing (12 inches OC is standard for driveways and garage floors), and calculate total linear feet in both directions. Add 10% for laps and waste. Use the rebar spacing calculator to get the exact count without doing the grid math by hand.

Should I charge for my estimating time?

Your estimating time is overhead. It’s real cost that should be baked into your overhead percentage, not something you do for free hoping to win the job. If you’re spending 3 hours building detailed bids on jobs you’re only winning 30% of, that overhead needs to show up in your pricing.

What’s the right profit margin on a concrete job?

Ten percent net profit is the floor. Fifteen to twenty percent is where you want to be on residential work, especially jobs with any complexity or tight access. Concrete is physical, time-sensitive work with real equipment and material costs. Price it accordingly.

Building a concrete estimate the right way isn’t complicated, but it requires discipline. Run the same checklist on every bid. Hit every line item. Apply your actual overhead and a real profit margin. That’s how you stay in business and build a reputation for reliable, accurate pricing.