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 It served as the base length unit in the now-superseded CGS (centimetre-gram-second) system used extensively in physics until the mid-20th century.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 micrometre?
A micrometre, also called a micron, is a unit of length equal to one millionth of a metre. It is used in microscopy, semiconductor fabrication, and the measurement of fine particles and biological cells.
Real-world uses
Micrometres (microns) are used to measure biological cells, bacteria, semiconductor chip features, and fine particle sizes in air quality monitoring. Paint film thickness, fibre diameters, and precision machining tolerances are also specified in µm.
History
The micrometre was formalized with SI prefix standardization in the 20th century. The term "micron" was officially revoked by the SI in 1967 in favour of "micrometre," though "micron" persists informally in many industries.
Common mistakes
Using the symbol "u" instead of the correct "µ" (Greek mu). Also, confusing micrometres with nanometres—a human hair is about 70 µm wide, not 70 nm.
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 micrometre
1 micrometre = 0.000001 metre
How to convert centimetre to micrometre
To convert centimetre to micrometre, multiply the value by 10,000.
To convert micrometre back to centimetre, multiply by 0.0001.
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 micrometre
| centimetre | micrometre |
|---|---|
| 0.1 | 1,000 |
| 0.5 | 5,000 |
| 1 | 10,000 |
| 2 | 20,000 |
| 5 | 50,000 |
| 10 | 100,000 |
| 25 | 250,000 |
| 50 | 500,000 |
| 100 | 1,000,000 |
| 250 | 2,500,000 |
| 500 | 5,000,000 |
| 1,000 | 10,000,000 |
Common values
| centimetre | micrometre | |
|---|---|---|
| Height of a door | 210 centimetre | 2,100,000 micrometre |
| Basketball court length | 2,800 centimetre | 28,000,000 micrometre |
| Football field (soccer) | 10,500 centimetre | 105,000,000 micrometre |
| Marathon distance | 4,219,500 centimetre | 4.219500e+10 micrometre |
| Altitude of a cruising airplane | 1,066,800 centimetre | 1.066800e+10 micrometre |