International System of Units
lastmod 2021-09-27created 2016-05-194 edits
The International System of Units (French: Système international d’unités, English: International System of Units, abbreviated SI) is a system of weights and measures, also called the MKS system of units (Metre-Kilogramme-Second). The International System of Units is today the system of weights and measures used worldwide, not only in everyday life but also widely in commerce and science. Systems of units had been divided between the meter system and the feet-pound system, but as part of the effort to create a single international system of units for the whole world, SI was adopted at the 11th General Conference on Weights and Measures (general conference of weights and measures) in October 1960.[1] Also, since the term SI itself already means "International System of Units", it is not called the "SI system of units".
Metric prefix
| 10n | Prefix | Symbol | Multiple | Decimal |
| 10<sup>24 | yotta | Y | septillion | 1 000 000 000 000 000 000 000 000 |
| 1021 | zetta | Z | sextillion | 1 000 000 000 000 000 000 000 |
| 1018 | exa | E | quintillion | 1 000 000 000 000 000 000 |
| 1015 | peta | P | quadrillion | 1 000 000 000 000 000 |
| 1012 | tera | T | trillion | 1 000 000 000 000 |
| 109 | giga | G | billion | 1 000 000 000 |
| 106 | mega | M | million | 1 000 000 |
| 103 | kilo | k | thousand | 1 000 |
| 102 | hecto | h | hundred | 100 |
| 101 | deca | da | ten | 10 |
| 100 | one | 1 | ||
| 10−1 | deci | d | tenth | 0.1 |
| 10−2 | centi | c | hundredth | 0.01 |
| 10−3 | milli | m | thousandth | 0.001 |
| 10−6 | micro | µ | millionth | 0.000 001 |
| 10−9 | nano | n | billionth | 0.000 000 001 |
| 10−12 | pico | p | trillionth | 0.000 000 000 001 |
| 10−15 | femto | f | quadrillionth | 0.000 000 000 000 001 |
| 10−18 | atto | a | quintillionth | 0.000 000 000 000 000 001 |
| 10−21 | zepto | z | sextillionth | 0.000 000 000 000 000 000 001 |
| 10−24 | yocto | y | septillionth | 0.000 000 000 000 000 000 000 001 |
See also
- ISO 8601 - An international standard for the representation of dates and times, established by the International Organization for Standardization (ISO).