Convert femtometer to millimeter Online | Free Length Converter

Femtometer

A femtometer (fm) is a unit of length in the metric system, equal to one-quadrillionth of a meter (1 fm = 10⁻¹⁵ meters). It is also known as a fermi, named after the physicist Enrico Fermi. Femtometers are used to measure extremely small distances at the subatomic level, such as the size of protons, neutrons, and atomic nuclei. For example, the radius of a proton is about 0.84 femtometers. This unit is commonly used in nuclear physics and particle physics, but it's far too small for everyday measurements.

Millimeter

A millimeter (mm) is a very small unit of length in the metric system. It is commonly used to measure tiny objects or precise dimensions. One millimeter is equal to one-thousandth of a meter (1 mm = 0.001 m), and 10 millimeters make 1 centimeter. Millimeters are often used in fields like engineering, machining, and science where exact measurements are important. For example, the thickness of a credit card is about 1 mm. The symbol for millimeter is "mm", and you can find it on most rulers or measuring tools. Since it allows for high accuracy, the millimeter is ideal for measuring small parts, gaps, or details.