What unit should I use to measure the length?

Common units for measuring length are millimeter (mm), centimeter (cm), decimeter (dm), kilometer (km) and so on. Length units play an important role in various fields. The unit of length refers to the basic unit for measuring spatial distance, which is formulated by human beings to standardize the length. Its international unit is the meter (symbol "meter").

Other units of length include: light years, astronomical units, meters (Pm), megameters (Mm), kilometers (km), decimeters (dm), centimeters (cm), millimeters (mm), silk rice (dmm), millet (cmm), micron (micron) and nanometer (nm).