The units in the SI system are referred to as basic units. Prefixes are added to the units to expand their use. Always use the correct case when using metric measurements and prefixes. 1Mm is 1 megameter and is very different from 1 mm (millimeter).
| Factor | Prefix | Symbol |
| 1 000 000 000 | giga | G |
| 1 000 000 | mega | M |
| 1 000 | kilo | k |
| 100 | hecto | h |
| 10 | deca | da |
| 1 | No prefix | |
| 0.1 | deci | d |
| 0.01 | centi | c |
| 0.001 | milli | m |
| 0.000 001 | micro | μ |
| 0.000 000 001 | nano | n |
