What is a Nanometer?

A nanometer (nm) is a unit of length in the metric system, equal to one billionth of a meter (1 x 10-9 m). Many have likely heard of it before–it’s frequently associated with nanotechnology and the creation or study of very tiny things. A nanometer is obviously smaller than a meter, but you may be wondering just how small? Or, what kinds of professions or real-world products work on this nanoscopic scale? Or, how it relates to other metric measurements of length?

Metric measurements are all based on the meter. Inspect any ruler or measuring tape, and you can see the numbered markings for meters, centimeters, and millimeters. With a mechanical pencil and steady hand, it’s not hard to draw lines one millimeter apart. Now imagine trying to fit one million parallel lines within the space of a millimeter–that’s a nanometer. Making those lines would definitely require specialized equipment since:

• A nanometer (nm) is smaller than a...
• micrometer (μm), which is smaller than a...
• millimeter (mm), which is smaller than a...
• centimeter (cm), which is smaller than a...
• decimeter (dm), which is smaller than a...
• meter (m).

Without the assistance of any tools (e.g. magnifying glasses, microscopes), a normal human eye (i.e. regular vision) is capable of seeing individual objects at about two hundredths of one millimeter in diameter, which is equal to 20 micrometers.

To give the size of 20 micrometers some context, see if you can identify a single cotton/acrylic fiber sticking out from a sweater (holding it up against a light source will help immensely) or floating in the air like dust. Or sift some fine sand in the palm of your hand to find the smallest, barely-perceptible grains. If those are a little tough to do, take a look at human hairs instead, which range from 18 micrometers (very fine) to 180 micrometers (very coarse) in diameter.

And all that is just the micrometer level — nanometer-sized objects are a thousand times smaller!

The nanoscale generally encompasses dimensions between one and 100 nanometers, which includes everything from atomic to cellular levels. Viruses range from 50 and 200 nanometers in size. The average thickness of a cell membrane is between 6 nanometers and 10 nanometers. A helix of DNA is about 2 nanometers in diameter, and carbon nanotubes can get as small as 1 nanometer in diameter.

Given those examples, it’s easy to understand that it requires high-powered and precise equipment (e.g. scanning tunneling microscopes) to interact with (i.e. image, measure, model, manipulate, and manufacture) objects on the nanoscopic scale. And there are people who do this everyday in fields such as:

• Chemistry
• Biology
• Physics
• Materials Science
• Engineering
• Technology

There are many examples of modern products made on the nanometer scale. Some medicines that small are designed to be capable of delivering drugs to specific cells. Modern synthetic chemicals are manufactured by a process that creates molecules with nanometer precision. Carbon nanotubes are used to improve thermal and electrical properties of products. And the Samsung Galaxy S8 smartphone and Apple iPad Pro tablet (second-gen) both feature processors designed at 10 nm.

The future has more in store for nanometer-sized scientific and technological applications. However, the nanometer isn’t even the smallest measurement around! Check the table below to see how it compares.