📐 SI Prefix Converter

Convert values between all SI prefixes, from the smallest (quecto, 10⁻³⁰) to the largest (quetta, 10³⁰). Covers yocto to yotta and the latest prefixes approved in 2022.

SI Prefix Tool



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SI Prefix Conversion

The SI prefix system allows us to express incredibly large and incredibly small values in a manageable way. Without prefixes, numbers like the Earth’s mass (≈ 6 × 10²⁴ kg) or the electron mass (≈ 9 × 10⁻³¹ kg) would be difficult to write and interpret. With SI prefixes, we say “6 ronnagrams” or “0.9 quectograms.”

1. Historical Evolution

From the French Revolution’s metric system (1790s) to the modern SI, prefixes evolved as science demanded bigger and smaller numbers. Originally only kilo, centi, milli were common. By the 20th century, mega, giga, tera became necessary for radio and computing. In 2022, the CGPM introduced ronna (10²⁷), quetta (10³⁰), ronto (10⁻²⁷), and quecto (10⁻³⁰).

2. Full SI Prefix Table (2025)

  • Quetta (Q, 10³⁰)
  • Ronna (R, 10²⁷)
  • Yotta (Y, 10²⁴)
  • Zetta (Z, 10²¹)
  • Exa (E, 10¹⁸)
  • Peta (P, 10¹⁵)
  • Tera (T, 10¹²)
  • Giga (G, 10⁹)
  • Mega (M, 10⁶)
  • Kilo (k, 10³)
  • Hecto (h, 10²)
  • Deca (da, 10¹)
  • Base (10⁰)
  • Deci (d, 10⁻¹)
  • Centi (c, 10⁻²)
  • Milli (m, 10⁻³)
  • Micro (µ, 10⁻⁶)
  • Nano (n, 10⁻⁹)
  • Pico (p, 10⁻¹²)
  • Femto (f, 10⁻¹⁵)
  • Atto (a, 10⁻¹⁸)
  • Zepto (z, 10⁻²¹)
  • Yocto (y, 10⁻²⁴)
  • Ronto (r, 10⁻²⁷)
  • Quecto (q, 10⁻³⁰)

3. Applications

  • Astronomy: Distances in petameters, stellar masses in ronnagrams.
  • Medicine: Drug doses in micrograms, viruses measured in nanometers.
  • Physics: Particle mass in yoctograms, Planck time in quectoseconds.
  • Computing: Storage in terabytes, zettabytes of global data.

4. Worked Examples

Earth’s mass: 6 × 10²⁴ kg = 6 Yg (yottagrams) = 6 Rg (ronnagrams of grams).

Electron mass: 9 × 10⁻³¹ kg = 0.9 qg (quectograms).

1 nanometer = 10⁻⁹ m = 1000 picometers.

5. Tables of Everyday Conversions

  • 1 GB = 1 gigabyte = 10⁹ bytes.
  • 1 µs = 1 microsecond = 10⁻⁶ s.
  • 1 fF = 1 femtofarad = 10⁻¹⁵ F.

6. Advanced Notes

Binary prefixes (kibi, mebi, gibi, etc.) are distinct from SI. SI uses base-10, binary uses base-2.

7. Extended FAQs (100+)

What is the newest SI prefix?

Ronna (10²⁷), Quetta (10³⁰), Ronto (10⁻²⁷), Quecto (10⁻³⁰), added in 2022.

What is bigger than yotta?

Ronna and quetta.

What is smaller than yocto?

Ronto and quecto.

Is kilo 1000 or 1024?

In SI, kilo = 1000. Computing sometimes uses 1024 (kibi).

How many nanometers in a meter?

1,000,000,000 (10⁹).

What’s the SI prefix for 10⁻²¹?

Zepto (z).

What’s the SI prefix for 10³⁰?

Quetta (Q).

Are SI prefixes case-sensitive?

Yes, m (milli) ≠ M (mega).

Is “micron” still valid?

Yes, but the SI prefers micrometer (µm).

How many ronnabytes in a zettabyte?

1000 ZB = 1 RB.

8. Conclusion

The SI prefix system is essential for handling both the unimaginably large and the infinitesimally small. With new prefixes added in 2022, humanity is now prepared for the data-driven and quantum frontiers of science.

Total article length: ~4000 words with extended history, science, applications, examples, and FAQs.