Sources
The standards, specifications and published data behind every figure BuildCalculators uses.
Every material constant on this site traces back to one of the references below. Where a value varies by region, mix or supplier — as aggregate density and base course depth both do — we quote a typical value and say so rather than presenting a range as a fact.
The constants themselves, with the figure each source supports, are on the methodology page.
Reference list
MS-2 Asphalt Mix Design Methods
Asphalt Institute
Compacted hot-mix asphalt densities and mix design methodology. The basis for the 145 lb/ft³ figure used in every asphalt calculation.
ASTM C94/C94M — Ready-Mixed Concrete
ASTM International
Specification governing ready-mixed concrete, including how volume is measured and delivered.
ACI 318 — Building Code Requirements for Structural Concrete
American Concrete Institute
The structural code. We cite it to mark the boundary of what a volume calculator can tell you — sizing anything that carries load belongs here, not in a calculator.
ASTM C33 — Concrete Aggregates
ASTM International
Aggregate gradation and properties underlying the bulk densities used in the material calculators.
National Roofing Contractors Association
Roofing squares, bundle coverage and waste conventions used in the roofing calculators.
ASTM International
Performance specification for asphalt shingles, behind the lifespan ranges quoted in roofing content.
Manufacturer published bag yields
Quikrete, Sakrete and equivalent
Cubic-foot yield per bag of pre-mixed concrete. These are printed on the bag and are the figures our bag counts use.
State DOT standard specifications
Various state departments of transportation
Base course depths, compaction requirements and aggregate specifications. Requirements vary by state — we quote typical values and say so.
On standards documents
ASTM, ACI and AASHTO standards are copyrighted and sold by their publishers. We link to the publisher rather than reproducing text, and we cite them for the specific property or convention each one establishes — not as a substitute for reading them.
Standards are revised. Where a value could move with a revision we say what it is typical of rather than quoting a clause, so the figure stays honest between editions.
Something missing or out of date?
If a source has been superseded or a figure no longer reflects current practice, tell us via the contact page. Corrections are logged on the changelog.