milliamps

Milliamps, abbreviated mA, are a unit of electrical current equal to one thousandth of an ampere. The term combines the prefix milli- (10^-3) with the base unit ampere. The plural form “milliamps” is common in spoken or informal writing, while the symbol mA is standard in technical contexts.

In the SI system, the ampere is the base unit of electric current, and the milliampere is a derived unit used for smaller currents. Conversions are straightforward: 1 A = 1000 mA, and 1 mA = 1000 µA (microamperes). This helps express currents that are too large for microamps but too small for full amperes.

Milliamps are widely used to describe currents in electronic circuits and devices where modest currents are involved. They appear in descriptions of LED operating currents, sensor outputs, small motors, and many battery-powered electronics. Typical values vary: LEDs often run at a few to a few tens of milliamps; microcontroller and peripheral components may draw from a fraction of a milliamp up to several milliamps depending on operation mode.

Measurement and safety: current is measured with instruments such as a digital multimeter in current mode, an ammeter, or a clamp meter. When dealing with AC, currents are usually specified as RMS (root mean square) values; DC currents are given as a direct value. Proper measurement requires selecting an appropriate range and observing correct polarity and safety practices to avoid short circuits or shocks.

See also: electrical current, amperes, microamps, measurement instruments, SI units.