Conversion method
Scale the same underlying unit by SI powers of ten. Prefix symbols are case-sensitive: M is mega, m is milli. Squared/cubed units require the prefix factor to be squared/cubed separately.
k = x × 1000
10 M = 10000 k.
| M | k |
|---|---|
| 1 | 1000 |
| 5 | 5000 |
| 10 | 10000 |
| 25 | 25000 |
| 50 | 50000 |
| 100 | 100000 |
Unit definitions and sources
Scale the same underlying unit by SI powers of ten. Prefix symbols are case-sensitive: M is mega, m is milli. Squared/cubed units require the prefix factor to be squared/cubed separately.
| Unit and system | Use | Definition | Relationship |
|---|---|---|---|
| Quetta (Q); si | Common units | Quetta: base (none) = value × 1e+30. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Ronna (R); si | Common units | Ronna: base (none) = value × 1e+27. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Yotta (Y); si | Specialist units | Yotta: base (none) = value × 1e+24. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Zetta (Z); si | Specialist units | Zetta: base (none) = value × 1e+21. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Exa (E); si | Specialist units | Exa: base (none) = value × 1e+18. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Peta (P); si | Specialist units | Peta: base (none) = value × 1000000000000000.0. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Tera (T); si | Specialist units | Tera: base (none) = value × 1000000000000.0. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Giga (G); si | Specialist units | Giga: base (none) = value × 1000000000.0. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Mega (M); si | Specialist units | Mega: base (none) = value × 1000000.0. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Kilo (k); si | Specialist units | Kilo: base (none) = value × 1000.0. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Hecto (h); si | Specialist units | Hecto: base (none) = value × 100.0. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Deca (da); si | Specialist units | Deca: base (none) = value × 10.0. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| No prefix (1); si | Specialist units | No prefix: base (none) = value × 1.0. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Deci (d); si | Specialist units | Deci: base (none) = value × 0.1. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Centi (c); si | Specialist units | Centi: base (none) = value × 0.01. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Milli (m); si | Specialist units | Milli: base (none) = value × 0.001. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Micro (µ); si | Specialist units | Micro: base (none) = value × 1e-06. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Nano (n); si | Specialist units | Nano: base (none) = value × 1e-09. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Pico (p); si | Specialist units | Pico: base (none) = value × 1e-12. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Femto (f); si | Specialist units | Femto: base (none) = value × 1e-15. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Atto (a); si | Specialist units | Atto: base (none) = value × 1e-18. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Zepto (z); si | Specialist units | Zepto: base (none) = value × 1e-21. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Yocto (y); si | Specialist units | Yocto: base (none) = value × 1e-24. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Ronto (r); si | Specialist units | Ronto: base (none) = value × 1e-27. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Quecto (q); si | Specialist units | Quecto: base (none) = value × 1e-30. Common use: SI Prefixes. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
Sources: BIPM: SI prefixes
Precision of SI prefixes conversions
All 25 SI prefixes units convert through No prefix (1). 25 have an exact defined relationship to the base unit and 0 are conventional or measured values. Results and the tables on this page come from the same engine, so a table value can be checked against the converter directly.
Standard display shows up to six decimal places, switching to scientific notation for very large or small values. Calculation uses JavaScript binary floating point independently of display rounding, so extra digits are not a claim about measurement accuracy. Each unit lists its own source; a citation records where the definition comes from, not an independent review. See Conversion methodology for the review and correction process.