Every range in this tool starts from a national U.S. price published by an independent cost source, then gets two simple adjustments: basement size (bigger spaces need more material and labor, roughly reflected in per-square-foot pricing of $3–$10) and a regional labor factor for your state — the Northeast, Pacific Northwest and Great Lakes typically run 15–30% above the national average, while much of the South and Southwest runs below it.

Per-item jobs — crack injection, sump pumps, wall reinforcement — aren’t size-adjusted, because you pay per crack, per pump, or per foot of wall. The result is an honest ballpark for budgeting and for sanity-checking contractor quotes. It is not a quote: your soil, foundation type, and problem severity can move the real number in either direction.