Prefix conversion is exponent conversion
An SI prefix scales a unit by an exact power of ten. CalcOS includes every current SI prefix from quecto at 10⁻³⁰ through quetta at 10³⁰, plus an unprefixed 10⁰ reference.
Prefix symbols are case-sensitive. For example, milli uses lowercase m and mega uses uppercase M; confusing them changes the multiplier by a factor of one billion.
Common SI decimal prefixes
| Prefix | Symbol | Exact multiplier |
|---|---|---|
| milli | m | 10⁻³ |
| micro | µ | 10⁻⁶ |
| kilo | k | 10³ |
| mega | M | 10⁶ |
| giga | G | 10⁹ |
| quetta | Q | 10³⁰ |
Decimal prefixes are not binary prefixes
SI prefixes use powers of ten. IEC binary prefixes use powers of two: kibi is 2¹⁰, mebi is 2²⁰, and so on through qubi at 2¹⁰⁰. CalcOS labels both systems in every selector and never interprets kilo as 1,024.
A prefix cannot stand alone in formal SI notation
This calculator compares prefix multipliers, but formal SI writing attaches the prefix directly to a unit name or symbol. Compound prefixes such as “millimicro” are not permitted; choose the single prefix representing the required power.
Authoritative references: BIPM SI Brochure, 9th edition, version 4.01, CGPM Resolution 3 (2022), and IEC 80000-13:2025.