SI Prefix Converter

Convert a value between SI prefixes from quecto to quetta, and between decimal SI and binary prefixes.

Convert between SI prefixes

Value

From prefix

To prefix

Result: —

Power of ten: —

Full name: —

Base units: —

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The full ladder runs from quecto at 10 to the minus 30 up to quetta at 10 to the 30, with binary prefixes alongside.

Common questions about the free online si prefix converter.

The full modern SI ladder from quecto at 10 to the minus 30 through micro, milli and kilo up to quetta at 10 to the 30.

Each prefix is a power of ten, so kilo means a thousand, mega a million and giga a thousand million, and they scale any unit.

Binary prefixes such as kibi and mebi are powers of 1024 rather than 1000, which is why a kibibyte is 1024 bytes and not 1000.

They are the smallest and largest SI prefixes, added so very tiny and very large measurements could be named clearly.

Yes. Pick one on each side and the tool converts through the base unit, so you can compare kilo with kibi directly.

Select the entry called no prefix, the base unit. The value is then treated as plain units with a factor of one.

Very large or very small results are written in exponential notation so the digits stay readable instead of running off the page.

Decimal prefixes show their exact exponent such as 10 to the 3, while binary prefixes show the power of two and its decimal equivalent.

No. The scaling is simple arithmetic performed in your browser, and the value you type is never transmitted.

Last updated: October 10, 2026