Astronomical Units to Miles (au to mi)

1 astronomical unit equals 92,955,807.27 miles (rounded).

1 astronomical unit = 92,955,807.27 miles

How to convert astronomical units to miles

To convert astronomical units to miles, multiply the number of astronomical units by 92,955,807.27. The factor is rounded to 10 significant digits. To go the other way, multiply miles by 1.075780018×10⁻⁸ (rounded).

miles = astronomical units × 92,955,807.27

Example: 10 astronomical units = 929,558,072.7 miles.

About these units

Astronomical Unit (au)

AstronomicalCurrent unit

Exactly 149,597,870,700 meters, roughly the average distance from the Earth to the Sun. Used for distances within the solar system.

Astronomers began calling it the astronomical unit in the mid-nineteenth century, with the name first recorded in 1848, though the quantity itself had been chased since antiquity. Aristarchus put the Sun 18 to 20 times farther away than the Moon, when the true ratio is about 389. Cassini and Richer used the parallax of Mars in 1672, transits of Venus served for generations, and radar echoes from Venus and Mars in the early 1960s finally gave direct distances.

For most of the twentieth century the unit was tied to the Gaussian gravitational constant, which meant its value had to be remeasured as observations improved. In 2012 the IAU removed that dependence by fixing it at exactly 149,597,870,700 meters and recommending the symbol au. The figure used here is that exact value. It is close to the mean Earth-Sun separation, which varies from about 0.983 au at perihelion to about 1.017 au at aphelion. Light needs roughly 499 seconds to cross one au, and Neptune orbits at about 30 au.

1 astronomical unit = 149,597,870,700 meters (exactly).

Sources: Wikipedia: Astronomical unit; NIST SP 811 Appendix B.8: factors for units outside the SI; Wikipedia: Light-second

Mile (mi)

US & ImperialCurrent unit

5,280 feet or 1,760 yards, exactly 1,609.344 meters. This is the statute (international) mile used on US and UK roads.

A thousand paces gave the mile its name. It descends from the Latin mille passus, the Roman mile, by way of Old English mil and Middle English myle. For centuries after Rome, miles of many lengths coexisted; a sixteenth-century Mercator map, for example, shows small, medium and large Flemish miles on a single scale bar. The English statute mile was fixed by an Act of Parliament under Elizabeth I in 1593, which declared that a mile contains eight furlongs, or 5,280 feet.

The 1959 international yard and pound agreement made that mile exactly 1,609.344 meters. A slightly longer US survey mile, about 1,609.347 meters, lingered in American land surveys and was slated for retirement from 1 January 2023. Today the mile is the road unit of the United Kingdom, the United States, Liberia and Myanmar, along with several territories such as the Bahamas, Belize, Guam and the US Virgin Islands. In Canada it survives chiefly in rail transport and horse racing.

1 mile = 1,609.344 meters (exactly).

Sources: Wikipedia: Mile; Wikipedia: Foot (unit); NIST Guide to the SI, Appendix B.8: conversion factors

Related conversions

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