How We Source Every Number

Every price and factor on this site traces back to a named U.S. government source. The table below is generated directly from the data file that powers the calculators — it updates automatically when a new niche is added. If a figure cannot be sourced to a named government publication, it does not appear on the site.

Sources in Active Use

What "Verified" Means

The verified date in the table above means a human opened the source URL, confirmed the figure was still published there, and recorded the current value. It does not mean the price changed on that date — BLS PPI updates monthly, BLS OEWS updates annually, USGS minerals data updates annually. The cadence column shows how often the underlying source publishes new figures.

If two government sources disagree, we use the more specific one and note the discrepancy in the derivation field of the price registry. We do not average conflicting sources.

How Prices Are Derived

Raw government index values (PPI series, OEWS wages) are not directly usable as calculator inputs — they need unit conversion and, for PPI, an anchor to an absolute base price. For each material we document the full derivation chain in the price registry: the index value, the base price source, the conversion math, and the range rationale. That derivation is visible in the site's source code at src/data/price_registry.json.

Regional Variation

National averages understate real price spread. Published BLS PPI series are national; regional breakdowns exist for some series and are used in the regional price tables where available. Where no regional data exists, we show the national midpoint as the default and give a range that reflects documented regional variance from USGS commodity statistics.

Labor Rates

Labor estimates use BLS OEWS median wages by occupation code (e.g., 47-2051 for Cement Masons, 47-2061 for Construction Laborers). The installed cost includes a contractor overhead and profit multiplier derived from RSMeans methodology ranges, applied to the BLS direct wage. The multiplier and productivity assumptions are documented in each material's derivation field.

Questions or Corrections

If a source URL is stale, a figure looks wrong, or a new niche is missing sources you'd expect to see here, send a correction and we'll update within 48 hours.