Metric Prefixes
| Decimal | Binary | ||||
|---|---|---|---|---|---|
| Power of 10 | Prefix | Symbol | Power of 2 | Prefix | Symbol |
| 30 | quetta- | Q | 100 | quebi- | Qi |
| 27 | ronna- | R | 90 | robi- | Ri |
| 24 | yotta- | Y | 80 | yobi- | Yi |
| 21 | zetta- | Z | 70 | zebi- | Zi |
| 18 | exa- | E | 60 | exbi- | Ei |
| 15 | peta- | P | 50 | pebi- | Pi |
| 12 | tera- | T | 40 | tebi- | Ti |
| 9 | giga- | G | 30 | gibi | Gi |
| 6 | mega- | M | 20 | mebi- | Mi |
| 3 | kilo- | k | 10 | kibi- | Ki |
| 2 | hecto- | h | None defined | ||
| 1 | deka- | da | None defined | ||
| 0 | No prefix | 0 | No prefix | ||
| -1 | deci- | d | No Diminishing Binary Prefixes Defined | ||
| -2 | centi- | c | |||
| -3 | milli- | m | |||
| -6 | micro- | μ | |||
| -9 | nano- | n | |||
| -12 | pico- | p | |||
| -15 | femto- | f | |||
| -18 | atto- | a | |||
| -21 | zepto- | z | |||
| -24 | yocto- | y | |||
| -27 | ronto- | r | |||
| -30 | quecto- | q | |||
The binary prefixes robi- (Ri) and quebi- (Qi) have not yet been officially adopted by the ISO (International Organization for Standardization) or IEC (International Electrotechnical Commission).
The prefixes hecto-, deka-, deci-, and centi- are disprefered in new contructed units.