Sources and data

Where a number may come from

In descending order of how freely it can be used:

• The reader. Dimensions, densities, swell factors, rates and prices are entered by the person using the tool. Nothing is pre-filled with an average.
• Definitions. A yard is three feet, a cubic yard is 27 cubic feet, an inch is 25.4 millimetres, a US short ton is 2,000 pounds. These are exact and need no source beyond the definition.
• Primary regulation and standards text. For example the federal gross, single-axle and tandem weight limits in 23 CFR § 658.17, cited with a link on the guide that uses them.
• A manufacturer’s data sheet, for that manufacturer’s own product. For example a bag of concrete mix yields a stated volume once mixed. It is used only for that product, as published, and the record notes that the manufacturer calls it approximate.
• Government datasets and public specifications. State transportation departments, public works agencies, the US Geological Survey and similar bodies, when a figure is needed that no reader could supply.
• A vendor’s own website, for statements about that vendor. Only on buyer’s guides, read directly and dated. See how we review software.

Where a number may not come from

• Another calculator, or a table copied by many sites. Published density and swell tables disagree with each other by wide margins, so picking one would mean choosing a winner among sources that genuinely conflict.
• A blog, a forum thread, a directory listing or a search-result snippet. These are where wrong prices and wrong product claims come from.
• Keyword-tool data. Search-demand figures decide what gets built. They are never used as a statement about construction or about a product.
• A number we produced by averaging, rounding or splitting a range. When a source publishes a range, the result is shown as a range.

The record every external figure carries

A number that did not come from the reader and is not a definition must have a complete record before it can ship: the organisation, the dataset, a link, the geography it covers, the period, the unit, any transformation we applied, its limitations, and the date we last verified it. A test fails the build if any field is empty. The record is shown on the page of the calculator that uses the figure.

Each record also says what kind of figure it holds, because a figure can be read first-hand and still be the wrong kind to present as a fact about your material. Your own figure: what you type. Manufacturer, standard or trade figure: a value for a well-defined product, such as a bag yield from the maker’s data sheet or a bar’s nominal weight from a standard. Agency planning factor: a convention a public agency uses to estimate quantities, payment or design under stated conditions; it holds for that agency, that material and that condition only, and is never shown as a general density. Candidate reference, not applied: read and recorded, never offered as a choice. Provenance unknown, not applied: its origin is not established, so it is never offered either. The kind is shown beside each source on the calculator page and in the table below.

What is in use right now

9 calculators on this site use external data. Each is documented in full on its own page.

Guides that cite a source do so in a sources list at the foot of the page. The cubic yards to tons calculator opens on the reader’s own density and offers no list of materials. It offers one agency reference, opt-in: Wisconsin DOT’s pay-quantity factor for in-place (compacted) Base Aggregate Dense, labelled as a pay-quantity factor and not a density. It does not apply to loose or delivered material, or to gravel or road base in general. A university table of volume-to-weight figures was read and is held as a candidate reference, not offered: it is an educational reference for onsite wastewater media and does not say where its figures come from or define the moisture and compaction its labels imply. Another reference will be added only when its source states the material and its condition.

Prices

Calculators publish none: every price field starts empty. On buyer’s guides, a price is a vendor’s own published price, quoted as printed, with the date it was read. A pricing page that lists no prices is recorded as exactly that, and a quote obtained by phone or from a third party is not repeated as the vendor’s price.

When there is no source

We say so. A software claim is one of three things: stated by the vendor, not published by the vendor, or not checked. A calculator that needs a value only you can supply reports what it is waiting for instead of filling the gap. A gap on the page is deliberate.

The rest of how this site works

• Editorial policy — What Calcumetryx publishes, the evidence a page needs before it goes live, and how advertising and the owner’s commercial interest are kept out of the content.
• How we review software — The evidence levels, the three states of a claim, and the rules for prices and rankings on buyer’s guides. No scores, no stars.
• Corrections policy — How to report an error in a calculation, a guide or a statement about a product, what we do about it, and the public log of changes.
• Who makes this site — Who publishes Calcumetryx, how AI assistance is used in drafting, and what credentials are and are not claimed.