What does nanometer mean?
A nanometer is a metric unit of length equal to one billionth of a metre, written 10⁻⁹ m or abbreviated nm. It is used to describe dimensions at the scale of atoms, molecules, microorganisms, and engineered nanomaterials, making it especially important in nanotechnology, microscopy, semiconductor manufacturing, and molecular biology. The unit is also used in descriptions of precision instruments and manufacturing processes, such as a microscope with nanometer-scale resolution. Because nanometer measurements are far smaller than a micrometer, they are primarily associated with scientific and technical contexts rather than everyday measurement. The term combines the prefix nano-, meaning one billionth, with metre, the base unit of length in the metric system.
nounA metric unit of length equal to one billionth of a metre (10⁻⁹ m), used especially in nanotechnology, physics, chemistry, and engineering.
- A metric unit of length equal to one billionth of a metre.
"The new microscope can resolve structures only a few nanometers across."
"Carbon nanotubes can have diameters of only a few nanometers."
"Manufacturing processes now achieve a resolution below 100 nanometers."
The usual plural in American English; British English uses nanometres.
"Several nanometers separate the layers in the material."
The nanometer is small enough to describe atoms and molecules, yet large enough to be a practical unit for designing microscopic machines.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does nanometer come from?
The word nanometer was formed in the 20th century from the prefix nano-, meaning one billionth, and the metric unit metre. The prefix nano- was adopted into the International System of Units as a standard decimal prefix in 1960, replacing longer or less systematic forms. The spelling nanometre reflects British usage, while nanometer is standard in American English.
Related word forms
How nanometer is actually used
The spelling is nanometer in US English and nanometre in British English. The abbreviation nm is common in technical and scientific writing.
Easily confused with nanometer
A nanometer is one billionth of a metre, whereas a micrometer is one millionth of a metre and therefore 1,000 times larger.
A nanometer is one billionth of a metre, while a millimeter is one thousandth of a metre, making a millimeter 1,000,000 times larger.