4 prefixes
Prefixes are short letter combinations placed before a unit to indicate multiples or fractions of that unit. They make it easier to express very large or very small quantities. The most common prefixes are shown in bold in the table below. For a fuller list extending orders of magnitude from 10^{-24} to 10^{24}, click the button below.
Prefixes
| Prefix | Symbol | Power of 10 | Common Example |
|---|---|---|---|
| yotta | Y | 10^{24} | YB, yottabyte (computing, data) |
| zetta | Z | 10^{21} | ZJ, zettajoule (astronomy, energy) |
| exa | E | 10^{18} | EW, exawatt (energy, power) |
| peta | P | 10^{15} | PB, petabyte (computing, data)** |
| tera | T | 10^{12} | TeV, teraelectronvolt (physics, energy) |
| giga | G | 10^{9} | GHz, gigahertz (electronics, frequency) |
| mega | M | 10^{6} | MW, megawatt (energy, power) |
| kilo | k | 10^{3} | km, kilometer (geography, length) |
| hecto | h | 10^{2} | hPa, hectopascal (meteorology, pressure) |
| deca | da | 10^{1} | dam, decameter (hydrology, length) |
| 10^{0} | m, meter (SI, length) | ||
| deci | d | 10^{-1} | dL, deciliter (chemistry, volume) |
| centi | c | 10^{-2} | cm, centimeter (biology, length) |
| milli | m | 10^{-3} | ms, millisecond (neuroscience, time) |
| micro | µ | 10^{-6} | µm, micrometer (microscopy, length) |
| nano | n | 10^{-9} | nm, nanometer (materials, length) |
| pico | p | 10^{-12} | pF, picofarad (electronics, capacitance) |
| femto | f | 10^{-15} | fs, femtosecond (physics, time) |
| atto | a | 10^{-18} | as, attosecond (quantum, time) |
| zepto | z | 10^{-21} | zm, zeptometer (physics, length) |
| yocto | y | 10^{-24} | yg, yoctogram (chemistry, mass) |
See here.
The most commonly used prefixes that we should be comfortable with are:
| Prefix | Symbol | Power of 10 | Common Example |
|---|---|---|---|
| tera | T | 10^{12} | TB, terabyte (information storage) |
| giga | G | 10^{9} | GHz, gigahertz (electronics, frequency) |
| mega | M | 10^{6} | MW, megawatt (energy, power) |
| kilo | k | 10^{3} | km, kilometer (geography, length) |
| 10^{0} | |||
| deci | d | 10^{-1} | dL, deciliter (chemistry, volume) |
| centi | c | 10^{-2} | cm, centimeter (biology, length) |
| milli | m | 10^{-3} | ms, millisecond (neuroscience, time) |
| micro | µ | 10^{-6} | µg, microgram (chemistry, mass) |
| nano | n | 10^{-9} | nm, nanometer (materials, length) |