US Construction Estimating Constants

A table of the constants that the TakeoffMetric calculators use to turn dimensions into order quantities: bag yields, aggregate and soil densities, swell and compaction ratios, rebar weights, dressed lumber sizes, block counts, mortar rules of thumb, paver base depths, shingle coverage, asphalt unit weights and air properties for duct sizing. Each row gives one value, its unit, an SI conversion, the condition it applies to, and a link to the primary source it was read from.

Compiled 2026-09-29 by TakeoffMetric Editorial (TakeOffMetrics Research). 148 rows.

Version 1.1.0 (2026-10-04). 55 of the 148 rows keep their source, link and dates but carry no value: their publishers' terms of use do not allow republication, or could not be read (values_withheld, withheld_hosts). The 93 other values are unchanged from 1.0.0. Row HVC-003 is now credited to its three authors (Liu, Long & Chen, 2012), and its quantity states that the figure is the roughness of the galvanized duct fittings in that study.

Version 1.1.1 (2026-10-09). Three source links that redirected now point to their final address, same document: the QUIKRETE No. 1101 data sheet (rows CON-001 to CON-005), NIST PS 20-20 Revision 1 (LUM-002 to LUM-016) and the archived GAF RESHR112 sell sheet (ROF-003). No value, unit or condition changed.

Version 1.2.0 (2026-10-11). Rows LUM-002 to LUM-016 now cite the current edition of the American Softwood Lumber Standard, NIST PS 20-25 (Table 3), which supersedes PS 20-20 Revision 1; the source was opened on 2026-10-01. The inch values are unchanged. The notes give the millimetre figure PS 20-25 prints, to the tenth, and the SI value of six rows (LUM-010 to LUM-013, LUM-015, LUM-016) moves by 0.1 mm to that printed figure. No other row changed.

Files

Columns

id · category · material_or_item · quantity · value · unit · value_si · unit_si · condition · source_publisher · source_title · source_url · source_type · date_opened · used_by_tool_url · engine_file · engine_symbol · notes · values_withheld · withheld_hosts

• value is written as the source prints it, in US customary units.
• value_si is a conversion of value with the exact NIST factors (1 lb = 0.45359237 kg, 1 ft = 0.3048 m), rounded to 4 significant digits. Where the source prints its own metric figure and it differs by rounding, notes gives it.
• source_type is one of federal_public_domain, manufacturer_datasheet, trade_association, supplier, other (university extension services, state DOT specifications, a peer-reviewed paper, a national laboratory resource).
• values_withheld is true when value and value_si are left empty because the publisher's terms of use forbid republication or could not be read; withheld_hosts names the domain(s) concerned. Read the value at source_url.
• used_by_tool_url, engine_file and engine_symbol may hold several entries separated by ; when more than one calculator uses the same value. The two engine columns point to the site's source code, which is not part of this package.

Method

• Every value was read in the source document itself on the date in date_opened, and recorded in the site's source ledger with the passage it came from. A URL that answers is not treated as a source; the value has to be on the page.
• Only values the ledger marks verified are included. Values a calculator treats as its own editable assumption (for example the 150 lb/ft³ default for concrete) are not included.
• Ratios such as loose-to-compacted volume are arithmetic on two values of the same source row; notes shows the division.
• Building-code provisions and published tables (IRC, AWC, the Brick Industry Association's quantity tables, the CMHA grout table) are not reproduced here; the calculator pages link to them.
• No passage from any source is copied here: value, unit and link only.
• Each value was checked on 2026-09-29 against the number the calculator code holds at engine_symbol: 148 of 148 matched in 1.0.0; the 93 values kept in 1.1.0 are those same values.
• On 2026-10-04 the terms of use of every publisher were looked up. A value is kept when it comes from a US federal publication (public domain), from a publisher whose terms allow reuse, or from a publisher that has no terms page; where the terms forbid republication or could not be read, the value is withheld.

How the calculators use these values is described on the methodology page.

Summary by category

By source type: manufacturer data sheet 44 · federal (public domain) 39 · trade association 37 · other 25 · supplier 3.

Calculators that read these values

Counted from the used_by_tool_url column: 19 calculator pages on takeoffmetric.com read at least one row of this table. A row that several calculators use is counted once for each of them.

Limits

• These are estimating values. Densities change with moisture, gradation and compaction; bag yields and coverage are for the named product line only. Confirm with your plans, your supplier and your local code before ordering or building.
• The condition column matters: a loose density, a bank density and a compacted density of the same material are different numbers, and using one for another changes the order quantity.
• FHWA Exhibit 5.1 A values describe highway embankment work. The calculators apply them as described in notes.

License

CC BY 4.0 covers the compilation: the selection and arrangement of the rows, the SI conversions, the conditions and the notes. It does not cover third-party values: values from US federal publications are government works in the public domain, and every other value stays under its publisher's terms, cited row by row through source_publisher and source_url. Cite as: TakeoffMetric Editorial, US Construction Estimating Constants, version 1.2.0, 2026, takeoffmetric.com.