The distinctive point
US liquid gallon: a rule rather than an average
The matrix treats this value as exact because its recorded basis is defined. The interesting distinction is epistemic: a defined standard can be converted without an uncertainty band, while reconstructed ancient standards cannot inherit that certainty.
Basis: defined. Check the record source.
- smallerUS liquid pint8 × US liquid pint
What this unit was
US liquid gallon is modelled here as a liquid standard of the Modern US customary tradition, associated with United States during Current international-inch definition. The converter represents one US gal as 3.7854118 L; its basis is defined. This is a defined or exact matrix anchor.
Its present role is chiefly comparative: it provides a stable reference for storage, rations, trade, and the circulation of drink or other commodities, rather than evidence that earlier cultures used a modern definition. A vessel name is not automatically the capacity of every surviving vessel.
Evidence of use and sources
The working value is traceable to NIST Handbook 44 Appendix C. Its record is classified as exact confidence and uses the stated basis rather than an assumed culture-wide constant.
The local library supplies contextual quotations; the linked record source remains authoritative for the modern definition.
“the ten millionth of the meridian quadrant ... be called a metre”
Standard measures of United States, Great Britain, and France, PDF p. 16. metric origin proposal
“A standard is a physical representation of a unit.”
A dictionary of weights and measures for the British Isles, PDF p. 31. standard versus unit
“the omission of necessary facts”
Standard measures of United States, Great Britain, and France, PDF p. 10. conditions required for comparison
Working definition
US liquid gallon is represented as a Modern US customary standard associated with United States during Current international-inch definition.
The converter uses 3.785411784 L per unit.
How to use it
Basis: defined; confidence: exact. A shared historical name does not make this value portable to another period or polity.
Open this unit in the Liquid converter · Return to all units