This page describes an obsolete unit.

The unit described on this page was in use prior to modern methods of precision measurement. It was based on a standard which is no longer available, and which is not capable of being calibrated against modern measurement units. Therefore, the equivalence to modern SI units or to current United States customary units can only be considered approximate.

The term Roman mile, or simply mile when the reference to Ancient Roman standards is obvious, is often used to translate the Latin mille passuum. However, it is not at all clear that one can consider this to be an actual Roman unit of length or distance. The Latin phrase simply means “1000 paces,” so that a distance given as “septem milia passuum,” though usually translated as “seven miles,” might with more accuracy be translated as “seven thousand paces.” Still, the Roman mile is so frequently cited as a unit that a page in this Wiki is devoted to it as though it were. And as well, many other civilizations have adopted a “mile” as a unit based upon the Roman mile, so that it needs to be considered if only for historical reasons.

Value in terms of modern unitsEdit

Of course, no actual Roman standards are definitively known by the present day, so that the only way of determining the length of the Roman mile is by measurement of distances which were given by the Romans in their miles. However, because the Romans were in the habit of putting mileposts on their roads, and these roads have, at least in some cases, survived to the present day, a measurement of the distances they indicate (though requiring statistical treatment to allow for the inaccuracies of the Romans' own measurements) gives the best estimate of the Roman mile as 1472 m = 1609.799 yd = 0.915 mi. This distance will be adopted on this wiki as the basis for interpreting all other Ancient Roman units of length or distance, as their relation to the mile is known.

Relation to other Ancient Roman unitsEdit

500 decempedae = 1 Roman mile