Unit Prefix Converter
Convert numeric values between SI (decimal) and IEC (binary) prefixes. Useful for science, engineering, and data-size conversions.
Examples: g, m, L, s, B
Enter a value to see conversion output.
Table of Contents
What is a Unit Prefix Converter?
A unit prefix converter changes the scale of a value while keeping the same base unit. For example, converting milligrams to kilograms keeps the base unit as grams, but changes the prefix from milli (10^-3) to kilo (10^3).
This is especially useful when working with very large or very small values where manual conversion is error-prone. The same applies to digital units where binary prefixes such as Ki and Mi follow powers of 2 rather than powers of 10.
How it Works
The converter uses a two-step process:
- Normalize: Convert the input value to the base unit.
- Scale: Divide by the target prefix factor to get the output.
When SI mode is selected, factors are powers of 10. In IEC mode, factors are powers of 2. This keeps results consistent with scientific and computing standards.
SI vs IEC Prefixes
SI Prefixes (Decimal)
Based on powers of 10.
- kilo (k) = 1,000
- mega (M) = 1,000,000
- milli (m) = 0.001
- micro (u) = 0.000001
IEC Prefixes (Binary)
Based on powers of 2.
- kibi (Ki) = 1,024
- mebi (Mi) = 1,048,576
- gibi (Gi) = 1,073,741,824
- tebi (Ti) = 1,099,511,627,776
Conversion Examples
SI: Milligrams to Kilograms
2,500,000 mg = 2.5 kg
Useful for lab and nutrition conversions.
SI: Microseconds to Seconds
750,000 us = 0.75 s
Useful in performance measurements.
IEC: MiB to KiB
8 MiB = 8,192 KiB
Useful for memory and storage sizing.
Common Use Cases
- Science & Labs: Convert nano, micro, milli, and kilo scales quickly.
- Engineering: Normalize units for calculations and reporting.
- Computing: Convert Ki/Mi/Gi values for memory and storage tasks.
- Education: Teach and verify prefix relationships with real examples.
- Documentation: Produce copy-ready values with clear unit symbols.
Frequently Asked Questions
MB (megabyte) commonly refers to decimal units (10^6 bytes), while MiB (mebibyte) is binary (2^20 bytes). They are close in value but not equal.
Yes. Switch prefix systems, set the same base unit symbol (for example, B), and convert values using each system’s factors.
The converter uses ASCII-friendly symbols for easier typing and copying in code and plain text environments where the micro symbol is less convenient.
No. All calculations happen in your browser. Input values are not uploaded or stored.