Roman Miles to Millimeters (mp to mm)

1 Roman mile equals 1,480,000 millimeters exactly.

1 Roman mile = 1,480,000 millimeters

How to convert Roman miles to millimeters

To convert Roman miles to millimeters, multiply the number of Roman miles by 1,480,000. This factor is exact. To go the other way, multiply millimeters by 6.756756757×10⁻⁷ (rounded).

millimeters = Roman miles × 1,480,000

Example: 10 Roman miles = 14,800,000 millimeters.

Approximate value. Standards for the Roman mile varied by place and period, so this converter uses the most commonly cited value. Treat results as estimates, not exact figures.

About these units

Roman Mile (mp)

Ancient RomanHistorical unit (no longer in standard use)Approximate value

'A thousand paces' (mille passus): 5,000 Roman feet, about 1.48 km. The word 'mile' comes from it, and Roman roads were marked with milestones at this interval.

Latin speakers called it mille passus, a thousand paces, usually abbreviated m.p. A pace was counted each time the same foot struck the ground, so it spanned two steps and was reckoned at five Roman feet, which made the mile 5,000 feet. The English word mile descends from the shortened form of the Latin phrase, through Old English mil.

The length rests on the Roman foot, and that foot is not fixed precisely. Modern estimates of the mile cluster near 1,480 m, one empirical figure being about 1,479 m, and this is the figure used here. Marcus Agrippa's standard foot of around 29 BC is credited with indirectly standardizing it, but measured surviving feet vary by a few millimetres, which shifts the mile by metres.

Stone markers stood at every mile along the empire's paved roads, measured out from the Golden Milestone in the Forum. Eight Roman stadia made a mile, and in Greek-speaking provinces it was rendered as the milion. At roughly 0.92 of an international mile, it survives in the name of the modern mile, though later European miles drifted to very different lengths.

1 Roman mile = 1,480 meters (approximately).

Sources: Wikipedia: Roman mile; Wikipedia: Roman units of measurement

Millimeter (mm)

Metric (SI)Current unit

One thousandth of a meter. Used in engineering, manufacturing and rainfall measurement.

Carl Friedrich Gauss put the millimeter at the base of his 1832 proposal for absolute units, pairing it with the milligram and the second, although the centimeter-based CGS system later won out among scientists. The name combines the metric prefix milli-, from the Latin for one thousand, with the meter. Since 1983 a millimeter has been tied to the speed of light: it is the distance light covers in 1/299,792,458,000 of a second.

Millimeters are the language of fine mechanical work. Standard rulers are divided into them, digital calipers commonly read to 0.01 mm, and mechanical pencil leads come in 0.5 and 0.7 mm. Copy paper is about 0.1 mm thick, and a thin hair, at 0.02 to 0.04 mm across, is close to the smallest thing the naked eye can see. A wave with a frequency of 300 GHz has a wavelength of 1 mm. An inch is exactly 25.4 mm. One trap for readers in the United States is that mil there traditionally means a thousandth of an inch, not a millimeter.

1 millimeter = 0.001 meters (exactly).

Sources: Wikipedia: Millimetre; Wikipedia: Centimetre-gram-second system of units; NIST Guide to the SI, Appendix B.8: conversion factors

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