The distinctive point
Roman cubitus: a value with room for evidence
The distinctive point is the uncertainty, not just the headline magnitude. The matrix carries ± 0.0015 m and names the basis as derived-from-pes. That keeps comparison possible without pretending that every specimen, survey, or period produced one perfect constant.
Basis: derived-from-pes. Check the record source.
- smallerRoman pes1.5 × Roman pes
- largerRoman passus1/3.3333 of Roman passus
What this unit was
Roman cubitus is modelled here as a length standard of the Roman tradition, associated with Roman Empire during Late Republic to Imperial representative. The converter represents one cubitus as 0.444 m; its basis is derived-from-pes. The matrix carries an indicative uncertainty of ± 0.0015 m.
Within that setting, the unit belonged to a working system for survey, building, travel, and the organisation of built space. It should be read with its period, locality, and evidential basis attached, not as a universal value shared by every culture using a similar name.
Evidence of use and sources
The working value is traceable to Smith Dictionary Mensura. Its record is classified as medium confidence and uses the stated basis rather than an assumed culture-wide constant.
Three directly pertinent excerpts from the supplied library are available.
“The rest of the Measures are founded on known proportions.”
Tables of antient coins, weights, and measures, PDF p. 78. reconstructed proportional systems
“Stadium contain'd 125 Roman Paces, or 625 Feet”
Tables of antient coins, weights, and measures, PDF p. 81. Roman distance relationship
“the trade value of the Attic standard, and ... the coinage value”
Flinders Petrie, Ancient Weights and Measures, PDF p. 31. trade and coin systems must be distinguished
Working definition
Roman cubitus is modelled here as a Roman length standard associated with Roman Empire and Late Republic to Imperial representative. The converter uses a representative value of 0.444 m per unit.
How to use it
This value is a contextual research aid, not a universal ruler. Its basis is recorded as derived from pes with medium confidence. One and one-half Roman feet
Open this unit in the converter · Return to all units
Next phase
This page will be expanded with source discussion, chronology, evidence, uncertainty notes, and worked examples.