Metric Prefixes
The metric system uses prefixes to indicate multiples and submultiples of base units. These prefixes are powers of 10 and make it easy to express very large or very small quantities.
| Prefix | Symbol | Factor | Decimal |
|---|---|---|---|
| yotta | Y | 10²⁴ | 1,000,000,000,000,000,000,000,000 |
| zetta | Z | 10²¹ | 1,000,000,000,000,000,000,000 |
| exa | E | 10¹⁸ | 1,000,000,000,000,000,000 |
| peta | P | 10¹⁵ | 1,000,000,000,000,000 |
| tera | T | 10¹² | 1,000,000,000,000 |
| giga | G | 10⁹ | 1,000,000,000 |
| mega | M | 10⁶ | 1,000,000 |
| kilo | k | 10³ | 1,000 |
| hecto | h | 10² | 100 |
| deca | da | 10¹ | 10 |
| (base unit) | — | 10⁰ | 1 |
| deci | d | 10⁻¹ | 0.1 |
| centi | c | 10⁻² | 0.01 |
| milli | m | 10⁻³ | 0.001 |
| micro | µ | 10⁻⁶ | 0.000001 |
| nano | n | 10⁻⁹ | 0.000000001 |
| pico | p | 10⁻¹² | 0.000000000001 |
| femto | f | 10⁻¹⁵ | 0.000000000000001 |
| atto | a | 10⁻¹⁸ | 0.000000000000000001 |
| zepto | z | 10⁻²¹ | 0.000000000000000000001 |
| yocto | y | 10⁻²⁴ | 0.000000000000000000000001 |
Examples
- 1 kilometer (km) = 1,000 meters (m)
- 1 milligram (mg) = 0.001 grams (g)
- 1 gigabyte (GB) = 1,000,000,000 bytes (B)
- 1 nanosecond (ns) = 0.000000001 seconds (s)