Nautical Miles to Micrometers (nmi to µm)

1 nautical mile equals 1,852,000,000 micrometers exactly.

1 nautical mile = 1,852,000,000 micrometers

How to convert nautical miles to micrometers

To convert nautical miles to micrometers, multiply the number of nautical miles by 1,852,000,000. This factor is exact. To go the other way, multiply micrometers by 5.399568035×10⁻¹⁰ (rounded).

micrometers = nautical miles × 1,852,000,000

Example: 10 nautical miles = 18,520,000,000 micrometers.

About these units

Nautical Mile (nmi)

NauticalCurrent unit

Exactly 1,852 meters, close to one minute of latitude. The standard unit of distance at sea and in aviation; one nautical mile per hour is one knot.

Sailors wanted a distance that matched their charts, so the nautical mile was tied to the globe itself: one minute of arc, one sixtieth of a degree, of latitude. Earth's polar circumference is therefore close to 21,600 nautical miles. Because Earth is flattened at the poles, a minute of latitude is about 1,843 meters at the equator and about 1,862 at the poles, so the fixed value of 1,852 meters is a compromise. France's definition of the meter produced a figure near 1,851.85 meters, which helped set the number.

The First International Extraordinary Hydrographic Conference in Monaco defined the international nautical mile as exactly 1,852 meters in 1929. The United States kept its own variant until 1954, and the United Kingdom adopted the international value in 1970. A speed of one nautical mile per hour is one knot. The unit is not part of SI but remains the norm in air, marine and space navigation and in defining territorial waters, because distances on a chart can be read straight off the latitude scale. Its symbols vary: NM, nmi and M all appear.

1 nautical mile = 1,852 meters (exactly).

Sources: Wikipedia: Nautical mile; NIST Guide to the SI, Appendix B.8: conversion factors

Micrometer (µm)

Metric (SI)Current unit

One millionth of a meter, also called a micron. Typical bacteria are a few micrometers long; a human hair is roughly 70 µm thick.

Two names, micron and micrometer, have shared this unit for more than a century. The prefix micro- was adopted in 1873 alongside the CGS system, and in 1879 the term micron and the symbol μ were officially accepted for the micrometer when used on its own. That created a clash once SI came along: μ was also the symbol for the prefix micro-. The 13th CGPM revoked micron and its symbol in 1967 to 1968, leaving micrometer and μm as the official name and symbol, though micron lives on in everyday speech.

A micrometer is a thousandth of a millimeter, and it is the natural scale for biology and filtration. A typical red blood cell is 6 to 8 μm across, a bacterium is 1 to 10 μm long, and a fog droplet is around 10 μm. Human hair ranges from about 17 to 181 μm in diameter, and paper is 70 to 180 μm thick. Infrared radiation is measured in micrometers of wavelength, and wool is graded by fibre width. Some American writers keep micron because micrometer also names the caliper-style measuring tool.

1 micrometer = 0.000001 meters (exactly).

Sources: Wikipedia: Micrometre; Wikipedia: Metric prefix

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