What is centimetre?
A centimetre is a metric unit of length equal to one hundredth of a metre. It is commonly used for everyday measurements such as clothing sizes, body height, and small object dimensions.
Real-world uses
Centimetres are widely used in clothing measurements, body height in medical records (outside the US), screen sizes in some markets, and school rulers. Tailors and dressmakers rely on centimetre tape measures for precise garment fitting.
History
The centimetre was established as part of the original metric system in the 1790s. It served as the base length unit in the now-superseded CGS (centimetre-gram-second) system used extensively in physics until the mid-20th century.
Common mistakes
Forgetting that there are 2.54 cm in one inch, not 2.5. Also, confusing cm² (area) with cm (length) when specifying material dimensions.
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?
Screen sizes, paper dimensions, and clothing measurements often require converting between centimetres and inches, especially when shopping internationally.
Worked examples
1 centimetre = 10,000,000 nanometre
1 nanometre = 1.000000e-09 metre
How to convert centimetre to nanometre
To convert centimetre to nanometre, multiply the value by 10,000,000.
To convert nanometre back to centimetre, multiply by 1.000000e-07.
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: centimetre to nanometre
| centimetre | nanometre |
|---|---|
| 0.1 | 1,000,000 |
| 0.5 | 5,000,000 |
| 1 | 10,000,000 |
| 2 | 20,000,000 |
| 5 | 50,000,000 |
| 10 | 100,000,000 |
| 25 | 249,999,999.99999997 |
| 50 | 499,999,999.99999994 |
| 100 | 999,999,999.99999988 |
| 250 | 2.500000e+09 |
| 500 | 5.000000e+09 |
| 1,000 | 1.000000e+10 |
Common values
| centimetre | nanometre | |
|---|---|---|
| Height of a door | 210 centimetre | 2.100000e+09 nanometre |
| Basketball court length | 2,800 centimetre | 2.800000e+10 nanometre |
| Football field (soccer) | 10,500 centimetre | 1.050000e+11 nanometre |
| Marathon distance | 4,219,500 centimetre | 4.219500e+13 nanometre |
| Altitude of a cruising airplane | 1,066,800 centimetre | 1.066800e+13 nanometre |