Skip to content

40x40 Concrete Slab Cost

A 40x40 concrete slab costs $13,681 to $22,802 installed at 5 inches with rebar. Enter a ZIP in the calculator to replace national labor rates with local ones.

Optional. Adds local labor rates.

Thickness
More optionsbroom · rebar · 4 in gravel
Finish
Reinforcement
Gravel base

LIKELY INSTALLED PRICE

$18,242

Our installed range for this 40×40 ft, 5-inch slab: $13,681 – $22,802 ($8.55 – $14.25 per sq ft)

In plain terms: that's about the size of a workshop or pole-barn floor, and roughly 43% of the price is the crew's labor.

DIY materials
$10,493
Concrete
24.69 yd³
Check a quote against this

An estimate, not a bid. A contractor's price depends on your site, access and timing.

Where the numbers come from

What changes the price

Where the money goes

  • Materials$8,695
  • Labor$6,507
  • Overhead and profit (20%)$3,040
All 8 line items
ItemQtyMaterialLaborTotal
Site setup, layout and cleanup1 job$100$56$156
Excavate and grade subgrade1,600 sqft$0$1,776$1,776
Forms, stakes and form release160 lf$192$355$547
Compacted crushed-stone base27.65 ton$1,244$512$1,756
#4 rebar, tied on chairs2213.33 lf$2,208$983$3,191
Ready-mix concrete, 3,500 psi, delivered25.93 yd3$4,510$576$5,086
Place, screed and broom finish1,600 sqft$80$2,072$2,152
Sawn control joints240 lf$360$178$538
Subtotal × overhead and profit (20%) = midpoint$18,242

National prices until you enter a ZIP.

Got a quote? Check it

Compare a contractor's price with the range for these inputs.

The quote includes:

What next

Get two or three quotes and compare them with $13,681 – $22,802. DIY: 1,223 bags or 25.93 yd³ of ready-mix.

Tell me when local quotes open

Quote matching is not live yet; we may earn a fee later.

Turn this price into an estimate for your customer →

Cost by thickness for 40x40 (1,600 sq ft)

  • 4 in · patios, sheds

    $12,766 – $21,276

    19.75 yd³ · 978 bags · about $17,021

  • 5 in · garages, driveways

    $13,681 – $22,802

    24.69 yd³ · 1,223 bags · about $18,242

  • 6 in · shops, RV pads

    $14,435 – $24,059

    29.63 yd³ · 1,467 bags · about $19,247

Typical use
An equipment barn or a multi-bay garage.
Thickness
5 inches with rebar; 6 inches or more under tractors and heavy machinery.
Planning note
Mark where any interior posts will land so the crew can thicken the slab under them.

Cost of a 40x40 concrete slab

At 1,600 square feet, concrete is the largest material line, followed by 2,214 linear ft of rebar and 27.7 tons of gravel. Finishing labor is the biggest labor line.

40x40 floor for a barn or shop

A square 40x40 fits several vehicles or a full workshop with open floor. Heavy tractors or lifts may need more than 5 inches; try it in the calculator.

Trucks, pump and crew

The pour needs 25.93 yd³ on 3 trucks. Access to the middle of a 40-foot square usually means a pump truck.

Estimate versus bid

This is an estimate from national wage and material data. It helps you budget and test bids, but it isn't a price offered to you.

DIY vs pro for this 40x40 pour

Materials alone come to $10,493, about 58% of the $18,242 midpoint contractor price. The difference is $7,749 of labor, equipment, delivery and contractor overhead across 8 line items. At 25.93 yd³ with waste the pour fills 3 mixer trucks, so ready-mix is the practical route even for a DIY pour.

Other popular slab sizes

Compare with the next sizes

Garage concrete slab cost calculatorAll slab sizes and the full calculator

Frequently asked questions

How many trucks for a 40x40 slab?

3 trucks for 25.93 yd³. The dispatcher will space them so the crew can keep up.

Is a 40x40 slab a DIY project?

Rarely. It needs a pump, several finishers and power trowels to finish before the concrete sets.

What does a 40x40 slab cost per square foot?

$8.55 – $14.25 at national prices, and less than small pads because setup is spread wider.

Should a 40x40 barn slab have a vapor barrier?

For storage or animals, it's optional. For a heated shop, it keeps moisture off tools and finishes.

For contractors

Quoting concrete for customers?

The free estimating app opens with a sample concrete job priced the same way. Read more about concrete estimating software.

Free estimating app →

Methodology. Quantities use the formulas on the methodology page; labor rates are BLS OEWS May 2025 medians for cement masons, material prices are our national estimates, marked estimated, until local prices are sampled, and the range widens with less local data. Prices updated September 2026.

Built and checked by the founder of American Build Rate. Page updated .