Unit Prefix Converter

SI (International System of Units) prefixes are standardized prefixes that indicate multiples or fractions of base units. For example, 'kilo' means 1000, 'mega' means 1,000,000, and 'milli' means 0.001.

Count the difference in powers of 10 between prefixes. From kilo (10³) to mega (10⁶), the difference is 3, so divide by 1000. From milli (10⁻³) to micro (10⁻⁶), the difference is -3, so multiply by 1000.

The largest SI prefix is yotta (Y), representing 10²⁴ or one septillion. It was added in 1991 and is commonly used for data storage discussions (yottabyte).

The smallest SI prefix is yocto (y), representing 10⁻²⁴. However, this calculator includes down to atto (10⁻¹⁸), which covers most common scientific applications.

One kilometer equals 1,000 meters. The prefix 'kilo' means 10³ or 1,000. This applies to any base unit: 1 kilogram = 1,000 grams, 1 kilobyte = 1,000 bytes, 1 kilowatt = 1,000 watts.

Milli (m) represents 10⁻³ or 0.001 (one thousandth), while micro (μ) represents 10⁻⁶ or 0.000001 (one millionth). So 1 millimeter = 1,000 micrometers, and micro is 1,000 times smaller than milli.

Hecto (10²) and deca (10¹) break the pattern of powers of 1,000 used in larger prefixes. Most applications prefer jumping from base units to kilo (10³). Exceptions include hectare in land measurement and decibel in acoustics, though technically decibel uses deci differently.

Binary prefixes use powers of 1,024 (2^10) instead of 1,000: kibi (KiB) = 1,024, mebi (MiB) = 1,048,576. SI prefixes use powers of 1,000: kilo (KB) = 1,000, mega (MB) = 1,000,000. This distinction is important in computing and data storage.

The Greek letter μ (mu) represents micro, meaning one millionth (10⁻⁶). Common uses include micrometers (μm) for measuring cells, microseconds (μs) for timing, and microamps (μA) for electrical current. In text, it's often written as 'u' when Greek letters aren't available.