Millimeter vs. Micron

Main Difference

The main difference between Millimeter and Micron is that the Millimeter is a unit of length 1/1000th of a metre and Micron is a one millionth of a metre.

• Millimeter

  The millimetre (International spelling as used by the International Bureau of Weights and Measures; SI unit symbol mm) or millimeter (American spelling) is a unit of length in the metric system, equal to one thousandth of a metre, which is the SI base unit of length. Therefore, there are one thousand millimetres in a metre. There are ten millimetres in a centimetre.

  One millimetre is equal to 1000 micrometres or 1000000 nanometres. A millimetre is equal to exactly ​5⁄127 (approximately 0.039370) of an inch.

• Micron

  The micrometre (International spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is an SI derived unit of length equaling 1×10−6 metre (SI standard prefix “micro-” = 10−6); that is, one millionth of a metre (or one thousandth of a millimetre, 0.001 mm, or about 0.000039 inch).

  The micrometre is a common unit of measurement for wavelengths of infrared radiation as well as sizes of biological cells and bacteria, and for grading wool by the diameter of the fibres. The width of a single human hair ranges from approximately 10 to 200 μm. The first and longest human chromosome is approximately 10μm in length.

• Micron (noun)

  a unit of length equal to one millionth of a metre, used in many technological and scientific fields.