length · International · Modern
SI base unit of length. Its definition fixes the speed of light in vacuum at exactly 299,792,458 m/s, with the second defined from the caesium-133 hyperfine frequency.
Converter
length · Ancient Greece / Rome · Antiquity
Roman mile (mille passus)
approx.
- Record
- M137
- Definition quality
- Historically reconstructed
- Conversion mode
- multiplicative
- Calculator
- Approximately calculable
Definition
One Roman mile (mille passus) is understood to be about 1,480 metres.
Approximate reference value
One Roman mile (mille passus) is understood to be about 1,480 metres.
History & use
Strong internal relation; metric value follows reconstructed foot.
Modern use
Retained primarily for historical, educational, or reference use rather than as a current standardized calculator unit.
Did you know?
Mille passus literally means 'a thousand paces'—but the Roman passus was a double-step of five Roman feet, so the mile contained 5,000 feet.
Sources & evidence
Source tier Tier B/C — recorded secondary/reference source · confidence High
- Source 1 — https://www.cambridge.org/core/journals/britannia/article/abs/british-section-of-the-antonine-itinerary/B64AD9343A80D33DECCDB7E383807469
- Source 2 — https://www.cambridge.org/core/journals/britannia/article/abs/lengthunits-in-roman-town-planning-the-pes-monetalis-and-the-pes-drusianus/361CB63B5CDAB4A69355BBF82E04CC51
- Trivia — https://penelope.uchicago.edu/Thayer/E/Roman/Texts/secondary/SMIGRA%2A/Passus.html
Related measurements
length · International · Modern
1 km = 1000 m by the SI prefix kilo-.
length · International · Modern
1 cm = 0.01 m by the SI prefix centi-.
length · International · Modern
1 mm = 0.001 m by the SI prefix milli-.
inch
inlength · UK / US · Modern / historical
1 international inch = exactly 0.0254 m.
foot
ftlength · UK / US · Modern / historical
1 international foot = exactly 0.3048 m.
yard
ydlength · UK / US · Modern / historical
1 international yard = exactly 0.9144 m.
mile
milength · UK / US · Modern / historical
1 international mile = exactly 1609.344 m = 1760 yd.