SlabCalc Concrete Cost Index: professional installed concrete flatwork cost per square foot across 30 US metros from 445 distinct state DOT unit-bid records (2021-2024 bids, 2025 dollars)

Metro-level index of professional installed concrete sidewalk and flatwork cost, in US dollars per square foot (low-high range), for 30 US metropolitan areas. Built from 445 distinct contractor unit-bid records — 617 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 17 state departments of transportation plus the New York City Department of Design and Construction, including FDOT, TxDOT, CDOT, NCDOT, Caltrans and IDOT. 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. Records from earlier lettings are inflation-adjusted to 2025 dollars using the US Bureau of Labor Statistics Producer Price Index for Ready-Mix Concrete, series WPU1333. Atlanta carries the largest single adjustment, a factor of 1.3069 applied to 2021 prices. Known limitations, stated up front: 21 metros are backed by a direct pull of metro- or district-specific bid tabulations, 8 are calibrated or transferred from a neighbouring jurisdiction, and Phoenix is modelled from regional labor and material indices with no direct DOT bid data because Arizona DOT publishes no bulk bid-tabulation export. The four Texas metros draw on a single statewide TxDOT dashboard and therefore carry identical figures, so metro-to-metro comparison within Texas is not meaningful. 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 28 September 2026. 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 $10.61/sq ft (was $11.07). Record count (445), range ($4.96-$38.00) and method otherwise unchanged.