SlabCalc Concrete Cost Index: professional installed concrete flatwork cost per square foot across 21 US metros from 396 distinct state DOT unit-bid records (2021-2026 bids, 2025 dollars)

Metro-level index of professional installed concrete sidewalk and flatwork cost, in US dollars per square foot (low-high range), for 21 US metropolitan areas, each priced from its own state department of transportation's bid data. Built from 396 distinct contractor unit-bid records (568 metro-level assignments, because the TxDOT, FDOT Tampa/Orlando and MoDOT statewide pools each back more than one metro), extracted from the published bid tabulations of 9 state departments of transportation (FDOT, TxDOT, CDOT, NCDOT, Caltrans, IDOT, MnDOT, MoDOT and Ohio DOT) plus the New York City Department of Design and Construction. These are the actual unit prices contractors submitted to win public concrete work, not survey estimates. Method: bid records are matched to the DOT line item corresponding to standard concrete flatwork placement, in most states a sidewalk item priced per square yard or cubic yard and converted to a per-square-foot basis. Single-year sources are inflation-adjusted to 2025 dollars using the US Bureau of Labor Statistics Producer Price Index for Ready-Mix Concrete, series WPU1333 (2024 sources: factor 1.0081). Sources spanning several years are not adjusted. Modelled metros, included in the file for reference but not part of the index (column "In index" = no): Atlanta, Philadelphia, Nashville, Boston, Detroit, Seattle, Portland and Las Vegas are modelled from another metro's DOT prices scaled by a BLS labor-cost ratio; Phoenix is modelled from national labor and material indices because Arizona DOT publishes no bulk bid-tabulation export. Known limitations: the four Texas metros draw on a single statewide TxDOT dashboard and therefore carry identical figures, as do Tampa/Orlando (FDOT) and St. Louis/Kansas City (MoDOT). DOT contracts are large-volume infrastructure placements and some require prevailing-wage labor; small residential jobs typically price above the low end of these ranges because minimum mobilisation costs dominate a small pour. Data last updated 29 September 2026. v1.2 (2026-09-29): Removed eight metros that earlier versions labelled as their own state DOT's bid tabulations but that were modelled from another metro's DOT prices by a labor-cost ratio (Atlanta, Philadelphia, Nashville, Boston, Detroit, Seattle, Portland, Las Vegas). Atlanta was Charlotte's 2024 NCDOT prices under a 2021 GDOT label and was inflated as 2021 data; it now equals Charlotte. The index now covers 21 metros; national median USD 9.63/sq ft (was USD 10.61); 396 distinct records from 9 state DOTs plus NYC DDC (was 445 from 17). Range (USD 4.96-USD 38.00) unchanged. The file keeps all 30 metros with an "In index" column. v1.1 (2026-09-28): Corrected the inflation series from BLS WPU1321 (construction sand, gravel and crushed stone) to WPU1333 (ready-mix concrete). 18 of 30 metros revised by -4.5% to -5.9%; 12 metros unchanged. Atlanta's 2021 factor is now 1.3069 (was 1.3684); 2024-source factor 1.0081 (was 1.0698). National median USD 10.61/sq ft (was USD 11.07). Record count (445), range (USD 4.96-USD 38.00) and method otherwise unchanged.