Concrete Cost Per Square Foot Calculator

See what a slab costs per square foot, installed, for your size, thickness and finish, and how that compares with typical prices.

A typical 4-inch concrete slab costs $7 to $13 per sq ft installed with a broom finish (based on a 20 × 20 ft slab). Small slabs cost more per foot because fixed costs are spread over less area. Change the size and options in the calculator below to see your own per-square-foot price.

Concrete Slab Cost & Volume Estimator

Precision multi-layer project budgeting: Materials, Sub-Base, Reinforcement, Labor & Equipment

Quick Project Presets

Picking a location sets the ready-mix, excavation and labor rates below to that area's typical level. You can still type your own local prices afterwards. Slab prices by state.

1. Slab Dimensions & Quantity
ft
ft
in
2. Concrete Material Type & Pricing
$
3. Project Scope, Reinforcement & Labor
$ /sq ft
inches
$ /yd³
$ /lin ft
$ /sq ft

Closer spacing uses more steel and raises the rebar cost.

$
$ /sq ft
$

Not charged when bagged concrete is selected.

$
$
$
$ /sq ft
%
%
Live Estimate
Estimated Total Project Budget
$4,253.36
$10.63 / sq. ft.
$114.46 / m²
Based on U.S. national average rates
Order Volume (w/ Waste)
5.43 yd³
Net: 4.94 yd³
Or Bagged Equivalent
245 bags
80-lb pre-mix bags
Total Surface Area
400 sq ft (37.2 m²)
Order volume: 4.15 m³
Estimated Wet Weight
21,267 lbs
Perimeter: 80 ft
Cost Distribution Breakdown
Concrete
Labor
Prep/Base
Rebar
Forms

A scaled plan of your slab: rebar grid at the spacing you chose, support chairs about every 3 to 4 ft, and the recommended control-joint saw cuts (2.5 times the thickness in inches, in feet, capped at 15 ft). It redraws as you change the inputs.

Cost per Square Foot by Thickness

Slab4 in5 in6 in
10 × 10 ft$8–$15$8–$15$9–$16
20 × 20 ft$7–$13$7–$14$8–$14
24 × 24 ft$6–$13$7–$14$7–$14
Installed low end: plain broom-finish slab with ready-mix at $150/yd³ plus a $120 delivery fee, forms and labor at $3.50/sq ft. High end: the calculator's default scope (adds a vapor barrier and #4 rebar at 18 in, labor at $5.00/sq ft) plus 25% contractor overhead and profit. DIY materials: the cheaper of ready-mix or $6.50 80-lb bags, plus forms, up to vapor barrier and rebar. Site excavation and a gravel base are extra (about $1.40 to $3.30 per sq ft).

Why the Per-Foot Price Changes

Concrete, rebar and finishing scale with area, but the delivery fee, the trip to the site and setup time do not. A 10 × 10 slab therefore works out to $8 to $15 per sq ft installed, while a 24 × 24 garage at 5 inches is $7 to $14. Use the per-foot price to compare quotes of a similar size, and use the total when the sizes differ. Our cost per square foot guide has the full matrix by finish.

Frequently Asked Questions

About $7 to $13 per sq ft installed for a 4-inch broom-finished slab, and $2.50 to $4.50 per sq ft in materials if you do it yourself.
Delivery fees, minimum charges and setup time are the same whether the slab is 100 or 400 sq ft, so they add more per foot on a small slab.
On a 20 x 20 ft slab, going from 4 to 6 inches moves the installed price from $7 to $13 to $8 to $14 per sq ft, mostly from the extra concrete.

Slab Estimating & Editorial Engineering Team

Construction Cost Estimators & Civil Engineering Analysts
Our team specializes in structural flatwork estimating, concrete mix designs, and civil building codes (ACI 302.1R, ASTM C94). All calculators and cost guides are rigorously validated against live contractor material price sheets, regional aggregate indexes, and real-world project bids.