What is micrometre?

A micrometre, also called a micron, is a unit of length equal to one millionth of a metre. It is used in microscopy, semiconductor fabrication, and the measurement of fine particles and biological cells.

Real-world uses

Micrometres (microns) are used to measure biological cells, bacteria, semiconductor chip features, and fine particle sizes in air quality monitoring. Paint film thickness, fibre diameters, and precision machining tolerances are also specified in µm.

History

The micrometre was formalized with SI prefix standardization in the 20th century. The term "micron" was officially revoked by the SI in 1967 in favour of "micrometre," though "micron" persists informally in many industries.

Common mistakes

Using the symbol "u" instead of the correct "µ" (Greek mu). Also, confusing micrometres with nanometres—a human hair is about 70 µm wide, not 70 nm.

What is nanometre?

A nanometre is a unit of length equal to one billionth of a metre. It is used to measure wavelengths of visible light, atomic radii, and dimensions of nanostructures in materials science.

Real-world uses

Nanometres are the standard unit in semiconductor fabrication (e.g., 5 nm chip processes), wavelength of visible light (380–700 nm), and molecular biology for measuring DNA strand widths and protein structures.

History

The nanometre gained prominence in the late 20th century with advances in electron microscopy and semiconductor technology. The prefix "nano-" comes from the Greek "nanos" meaning dwarf. It was officially adopted as an SI prefix in 1960.

Common mistakes

Confusing nanometres with angstroms—1 nm equals 10 angstroms. People also mistakenly equate "nano" products in marketing with actual nanometre-scale technology, which is not always the case.

When is this conversion used?

Converting micrometre to nanometre is useful in the length domain when comparing values across different measurement standards or applying formulas that require a specific unit.

Worked examples

1 micrometre = 1,000 nanometre

1 nanometre = 1.000000e-09 metre

How to convert micrometre to nanometre

To convert micrometre to nanometre, multiply the value by 1,000.

To convert nanometre back to micrometre, multiply by 0.001.

Measurement standards

The metre is one of seven SI base units, maintained by the International Bureau of Weights and Measures (BIPM). Since 2019, it is defined by fixing the numerical value of the speed of light in vacuum to exactly 299,792,458 metres per second.

Did you know?

A human hair is roughly 70 micrometres wide, while a single gold atom measures about 0.144 nanometres in diameter — meaning you could line up nearly half a million atoms across the width of one hair.

Quick reference: micrometre to nanometre

micrometrenanometre
0.1100
0.5500
11,000
22,000
55,000
1010,000
2525,000
5050,000
100100,000
250250,000
500500,000
1,0001,000,000

Common values

micrometrenanometre
Height of a door2,100,000 micrometre2.100000e+09 nanometre
Basketball court length28,000,000 micrometre2.800000e+10 nanometre
Football field (soccer)105,000,000 micrometre1.050000e+11 nanometre
Marathon distance4.219500e+10 micrometre4.219500e+13 nanometre
Altitude of a cruising airplane1.066800e+10 micrometre1.066800e+13 nanometre