Prefixes Converter
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Metric prefixes (also known as SI prefixes) are standardized decimal unit prefixes adopted by the International Bureau of Weights and Measures (BIPM) and the General Conference on Weights and Measures (CGPM). Placed before any International System of Units (SI) base unit — such as meters (m), grams (g), bytes (B), watts (W), hertz (Hz), seconds (s), or farads (F) — metric prefixes express multiples and submultiples in exact powers of 10, ranging from Quetta (1030) down to Quecto (10-30).
Our free online Prefixes Converter provides instant, high-precision conversions between all 24 official SI metric prefixes:
- Multiples (Large Scale): Kilo (103), Mega (106), Giga (109), Tera (1012), Peta (1015), Exa (1018), Zetta (1021), Yotta (1024), Ronna (1027), Quetta (1030).
- Submultiples (Small Scale): Deci (10-1), Centi (10-2), Milli (10-3), Micro (10-6), Nano (10-9), Pico (10-12), Femto (10-15), Atto (10-18), Zepto (10-21), Yocto (10-24), Ronto (10-27), Quecto (10-30).
Complete Master List of Official SI Metric Prefixes
Below is the complete official CGPM table of all 24 metric prefixes, including symbols, decimal factors, scientific powers of 10, and short-scale naming:
| Prefix Name | Symbol | Power of 10 | Decimal Value / Multiplier | Adopted Year (CGPM) | Short-Scale Number Name |
|---|---|---|---|---|---|
| quetta | Q | 1030 | 1,000,000,000,000,000,000,000,000,000,000 | 2022 | Nonillion |
| ronna | R | 1027 | 1,000,000,000,000,000,000,000,000,000 | 2022 | Octillion |
| yotta | Y | 1024 | 1,000,000,000,000,000,000,000,000 | 1991 | Septillion |
| zetta | Z | 1021 | 1,000,000,000,000,000,000,000 | 1991 | Sextillion |
| exa | E | 1018 | 1,000,000,000,000,000,000 | 1975 | Quintillion |
| peta | P | 1015 | 1,000,000,000,000,000 | 1975 | Quadrillion |
| tera | T | 1012 | 1,000,000,000,000 | 1960 | Trillion |
| giga | G | 109 | 1,000,000,000 | 1960 | Billion |
| mega | M | 106 | 1,000,000 | 1960 | Million |
| kilo | k | 103 | 1,000 | 1795 | Thousand |
| hecto | h | 102 | 100 | 1795 | Hundred |
| deka | da | 101 | 10 | 1795 | Ten |
| Base Unit (none) | — | 100 | 1 | — | One |
| deci | d | 10-1 | 0.1 | 1795 | Tenth |
| centi | c | 10-2 | 0.01 | 1795 | Hundredth |
| milli | m | 10-3 | 0.001 | 1795 | Thousandth |
| micro | μ | 10-6 | 0.000001 | 1960 | Millionth |
| nano | n | 10-9 | 0.000000001 | 1960 | Billionth |
| pico | p | 10-12 | 0.000000000001 | 1960 | Trillionth |
| femto | f | 10-15 | 0.000000000000001 | 1964 | Quadrillionth |
| atto | a | 10-18 | 0.000000000000000001 | 1964 | Quintillionth |
| zepto | z | 10-21 | 0.000000000000000000001 | 1991 | Sextillionth |
| yocto | y | 10-24 | 0.000000000000000000000001 | 1991 | Septillionth |
| ronto | r | 10-27 | 0.000000000000000000000000001 | 2022 | Octillionth |
| quecto | q | 10-30 | 0.000000000000000000000000000001 | 2022 | Nonillionth |
Step-by-Step Calculation Example
To convert 15 Gigabytes (GB) to Megabytes (MB):
15 Giga × (109 / 106) = 15 × 1,000 = 15,000 Megabytes
Thus, 15 GB is equal to exactly 15,000 MB.
Real-World Physical & Scientific Scale Benchmarks
Metric prefixes map directly to real-world phenomena across astronomy, computing, particle physics, and biology:
| Metric Scale / Prefix | Power of 10 | Real-World Physical & Computing Application |
|---|---|---|
| Quettagram (Qg) | 1030 g | Mass of planet Jupiter (≈ 1.9 Quettagrams) |
| Ronnagram (Rg) | 1027 g | Mass of planet Earth (≈ 5.97 Ronnagrams = 6 Rg) |
| Zettabyte (ZB) | 1021 Bytes | Global internet data traffic created annually (≈ 120 Zettabytes) |
| ExaFLOPS (EFLOPS) | 1018 FLOPS | Exascale supercomputer calculation speed (1 Quintillion ops/sec) |
| Terabyte (TB) | 1012 Bytes | High-capacity consumer solid-state drive (SSD) storage |
| Gigahertz (GHz) | 109 Hz | Modern computer CPU clock frequency (3.5 GHz = 3.5 Billion cycles/sec) |
| Nanometer (nm) | 10-9 m | Semiconductor microchip transistor gate node size (3 nm) |
| Femtometer (fm) | 10-15 m | Radius of an atomic proton / atomic nucleus (1.75 fm) |
| Rontogram (rg) | 10-27 g | Mass of a single electron (≈ 0.91 rontogram = 0.91 × 10-27 g) |
History & Standards: French 1795 Revolution vs. 2022 CGPM Update
The 1795 French Metric System Origin
The original metric prefix system was created during the French Revolution in 1795. It included just six prefixes: kilo, hecto, deka for multiples (derived from Greek roots) and deci, centi, milli for submultiples (derived from Latin roots).
The 2022 CGPM Expansion (Quetta, Ronna, Ronto, Quecto)
In November 2022, at the 27th General Conference on Weights and Measures (CGPM) in Versailles, international scientists voted unanimously to add four new prefixes: ronna (1027), quetta (1030), ronto (10-27), and quecto (10-30). This historic expansion was driven by exponential growth in global digital data (preventing unofficial terms like “brontobyte”) and quantum physics measurements.
To convert mega and kilo values directly, visit our Mega to Kilo Converter. For digital data conversions, check our Giga to Mega Converter or Tera to Giga Converter. For microscopic lengths, explore our Nano to Micro Converter or Conversion Calculator.
Frequently Asked Questions (FAQ)
What are the newest SI metric prefixes added in 2022?
The CGPM added four new official prefixes in 2022: ronna (1027), quetta (1030), ronto (10-27), and quecto (10-30).
How many Megabytes (MB) are in 1 Gigabyte (GB)?
There are exactly 1,000 Megabytes (MB) in 1 Gigabyte (GB) under the standard SI decimal metric system (or 1,024 MiB in binary kibibytes).
What is the mass of Earth in metric ronnagrams?
The Earth’s mass is approximately 5.97 × 1024 kg, which equals exactly 5.97 ronnagrams (Rg) (or ~6 Rg).
What is the symbol for micro in SI prefixes?
The symbol for micro is the Greek letter μ (mu), representing 10-6 (one millionth).