A taximeter or fare meter is a mechanical or electronic device installed in taxicabs and auto rickshaws that calculates passenger fares based on a combination of distance travelled and waiting time. Its shortened form, "taxi", is also a metonym for the hired cars that use them.

The modern taximeter was invented by German Friedrich Wilhelm Gustav Bruhn in 1891, and the Daimler Victoria—the world's first meter-equipped (and gasoline-powered) taxicab—was built by Gottlieb Daimler in 1897.

Taximeters were originally mechanical and mounted outside the cab, above the driver's side front wheel. Meters were soon relocated inside the taxi, and in the 1980s electronic meters were introduced. There are some companies that claiming invention of the world's first electronic taximeter including Monitex in Israel.

Constant expressed in pulses per kilometre which represents the number of pulses the taximeter must receive in order to correctly indicate a distance traveled of one kilometre.

Taximeters, when they are installed to the taxis, require adjustment of k constant. During the movement, car generates signal which transmitted to the taximeter. Number of signals transmitted per k constant ratio results distance travelled. Within pre-installed tariff values and travel data are multiplied and fare is calculated.^{[citation needed]}

Taximeters can include several accessories, or act as components in larger dispatching/control systems. Features include:

During normal operation, taximeters repeat cyclically through several stages: