What is metre?
The metre is the SI base unit of length. It is used globally in science, engineering, geography, and everyday measurement as the standard reference for distance.
Real-world uses
The metre is the standard unit for everyday measurements worldwide, from room dimensions and furniture sizes to athletic track events like the 100 m sprint. Engineers, architects, and scientists use it as the fundamental length reference in the SI system.
History
Originally defined in 1793 during the French Revolution as one ten-millionth of the distance from the North Pole to the equator along a meridian through Paris. Since 1983, it is defined by the speed of light in vacuum.
Common mistakes
Confusing "meter" (the measuring device) with "metre" (the unit of length) in British English. Also, people sometimes incorrectly assume 1 metre equals exactly 3 feet; it is actually about 3.281 feet.
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?
This conversion is frequently needed in construction, architecture, and real estate where building codes may specify dimensions in one system while materials are sold in another.
Worked examples
1 metre = 999,999,999.99999988 nanometre
1 nanometre = 1.000000e-09 metre
How to convert metre to nanometre
To convert metre to nanometre, multiply the value by 999,999,999.99999988.
To convert nanometre back to metre, multiply by 1.000000e-09.
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: metre to nanometre
| metre | nanometre |
|---|---|
| 0.1 | 100,000,000 |
| 0.5 | 499,999,999.99999994 |
| 1 | 999,999,999.99999988 |
| 2 | 2.000000e+09 |
| 5 | 5.000000e+09 |
| 10 | 1.000000e+10 |
| 25 | 2.500000e+10 |
| 50 | 5.000000e+10 |
| 100 | 1.000000e+11 |
| 250 | 2.500000e+11 |
| 500 | 5.000000e+11 |
| 1,000 | 1.000000e+12 |
Common values
| metre | nanometre | |
|---|---|---|
| Height of a door | 2.1 metre | 2.100000e+09 nanometre |
| Basketball court length | 28 metre | 2.800000e+10 nanometre |
| Football field (soccer) | 105 metre | 1.050000e+11 nanometre |
| Marathon distance | 42,195 metre | 4.219500e+13 nanometre |
| Altitude of a cruising airplane | 10,668 metre | 1.066800e+13 nanometre |