Nanometer (nm) Converter
Enter a length in any unit and this calculator converts it to all common metric and imperial units. The result panel shows picometers, angstroms, micrometers, millimeters, centimeters, meters, kilometers, inches, feet, yards and miles. For wavelengths between 380 nm and 700 nm the tool also identifies the visible-light color band. A step-by-step panel shows the exact conversion factor used, and a reference table lists common nano-scale objects for context.
What is a nanometer?
A nanometer (symbol: nm) is one billionth of a meter, or 10⁻⁹ m. The prefix "nano" comes from the Greek word for dwarf, and in the International System of Units (SI) it denotes a factor of 10⁻⁹. One nanometer is 1,000 times smaller than a micrometer, 1,000,000 times smaller than a millimeter, and 10 times larger than one angstrom. At this scale, individual atoms are just a fraction of a nanometer across (hydrogen has a radius of about 0.053 nm), while familiar nano-scale structures include DNA (2 nm wide), proteins (1-100 nm), viruses (20-300 nm), and modern semiconductor transistors (2-5 nm gate length). The nanometer is also the standard unit for expressing the wavelength of light: the visible spectrum runs from about 380 nm (violet) to 700 nm (red).
How to convert nanometers
Every conversion involves multiplying or dividing by a power of 10 within the metric system, or applying a fixed factor for imperial units. The key relationships are: 1 nm = 1,000 pm (picometers); 1 nm = 0.1 Å (angstroms - note that 10 nm = 1 Å is a common inversion error); 1 nm = 0.001 um (micrometers); 1 nm = 10⁻⁶ mm; 1 nm = 10⁻⁹ m. For imperial conversions: 1 inch = 25,400,000 nm exactly (since 1 inch = 25.4 mm and 1 mm = 1,000,000 nm), so 1 nm = 1/25,400,000 in = approximately 3.937 x 10⁻⁸ inches. This calculator handles all of these conversions simultaneously and shows the step-by-step factor for the unit you chose.
Nanometers in optics and light
The electromagnetic spectrum is most naturally described in nanometers for wavelengths between about 10 nm (extreme UV / soft X-ray boundary) and 1,000 nm (near-infrared). Human vision covers roughly 380-700 nm. Within that range: violet is 380-450 nm, blue is 450-495 nm, green is 495-570 nm, yellow is 570-590 nm, orange is 590-625 nm, and red is 625-700 nm. Laser pointers, LED specifications, fluorescent dyes, and solar cell efficiency curves all use nm as the standard wavelength unit. When you enter a value in the 380-700 nm range, this calculator identifies the corresponding color band automatically.
Nanometers in semiconductor technology
The "nm node" used by chip manufacturers such as TSMC, Intel, and Samsung refers to the minimum feature size of transistors on a chip. A 3 nm process node means the gate length of a transistor is approximately 3 nm, though the exact physical dimension varies by manufacturer and generation. A modern smartphone chip contains billions of transistors, each smaller than a typical virus. The angstrom (0.1 nm) is sometimes used alongside the nanometer for atomic-resolution measurements in crystallography and scanning-probe microscopy.
Common nano-scale objects
| Object | Approximate size | Notes |
|---|---|---|
| Hydrogen atom radius | 0.053 nm | Smallest atom by radius |
| Carbon-carbon bond | 0.154 nm | Typical C-C single bond |
| DNA double helix width | 2 nm | Roughly 10 base pairs wide |
| DNA base pair spacing | 0.34 nm | Distance along the helix axis |
| Protein (small, e.g. insulin) | ~3 nm | Globular proteins vary 1-100 nm |
| Transistor gate (2024 node) | 2-5 nm | Modern semiconductor node size |
| COVID-19 virus diameter | ~100 nm | Range 80-120 nm |
| Influenza virus | ~100 nm | Range 80-120 nm |
| Hemoglobin molecule | ~5 nm | Oxygen-carrying blood protein |
| Wavelength: violet light | 380-450 nm | Shortest visible wavelength |
| Wavelength: green light | 495-570 nm | Peak human eye sensitivity |
| Wavelength: red light | 620-700 nm | Longest visible wavelength |
| E. coli bacterium length | ~2,000 nm | = 2 um; just outside nano range |
Approximate sizes of real-world objects at the nanometer scale.
Frequently asked questions
How many nanometers are in a meter?
There are exactly 1,000,000,000 (one billion) nanometers in one meter. Equivalently, 1 nm = 10⁻⁹ m. To convert meters to nanometers, multiply by 1,000,000,000; to convert nanometers to meters, divide by 1,000,000,000.
How do I convert nm to micrometers (um)?
Divide the nanometer value by 1,000. One micrometer equals 1,000 nm, so 500 nm = 0.5 um. Micrometers are often used for biological cell sizes: a red blood cell is about 6,000-8,000 nm (6-8 um) in diameter.
What is the difference between a nanometer and an angstrom?
An angstrom (symbol Å) equals 0.1 nm, or one ten-billionth of a meter (10⁻¹⁰ m). So 1 nm = 10 Å, and 1 Å = 0.1 nm. The angstrom is widely used in crystallography and atomic physics because atomic radii and bond lengths are typically 0.5-3 Å. It is not an SI unit but is accepted for use with SI in the field of atomic-scale measurement.
How many nanometers in an inch?
One inch equals exactly 25,400,000 nm (25.4 mm x 1,000,000 nm/mm). Going the other way, 1 nm = approximately 3.937 x 10⁻⁸ inches, or about 0.0000000394 inches.
What wavelength of light is 550 nm?
550 nm falls in the green part of the visible spectrum (495-570 nm). It is close to the peak sensitivity of the human eye under daylight (photopic) conditions, which is around 555 nm. Laser pointers that emit green light typically operate at 532 nm or 543 nm.
Can I convert from meters or inches to nanometers?
Yes. Use the "Convert from" selector to choose your starting unit (meters, inches, feet, or any other supported unit), enter the value, and the calculator converts it to nanometers and all other units simultaneously.
What is the nanometer used for in semiconductor manufacturing?
In chip manufacturing, the "nm node" denotes the approximate minimum transistor feature size. A 3 nm process can fit billions of transistors onto a fingernail-sized chip. The industry has used nanometer labeling since the 1990s, though modern "nm" labels are increasingly marketing shorthand and may not correspond exactly to any single physical dimension.