What does wattmeter mean?
A wattmeter is an instrument for measuring power, usually electrical power expressed in watts. Unlike a voltmeter, which measures potential difference, a wattmeter indicates the rate at which electrical energy is transferred or consumed. Engineers use it to test circuits, verify the output of generators and power supplies, and monitor consumption in electrical equipment. The name is a transparent compound: watt names the unit of power, while meter names the measuring instrument. Although often associated with laboratory instruments, wattmeters also appear in industrial panels, electrical installations, and consumer testing equipment. The term is technical and most natural in engineering, electronics, and scientific contexts rather than ordinary conversation. Its usefulness lies in providing a direct reading of power, which cannot be determined from voltage alone without additional information about current and their relationship.
nounA wattmeter is an instrument for measuring power, especially electrical power expressed in watts.
- An instrument designed to measure power, especially electrical power in watts.
"The engineer connected the wattmeter before switching on the load."
"Connect the wattmeter before switching on the load."
"The engineer calibrated the wattmeter and recorded its reading at 250 watts."
The standard plural is wattmeters.
"Several wattmeters were connected to the test panel."
A wattmeter reveals how much power is actually being used—not merely the voltage pushing it through the circuit.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does wattmeter come from?
Wattmeter is a compound of watt, the unit of power named after James Watt, and meter, a device used for measuring. The compound developed with the growth of electrical measurement in the nineteenth century. Its second element comes through the English word meter, which ultimately reflects the Greek metron, meaning “measure.”
How wattmeter is actually used
This is primarily a technical term used in electrical engineering, electronics, and laboratory work rather than in everyday speech.
Easily confused with wattmeter
A wattmeter measures power, usually in watts, whereas a watermeter measures the flow or volume of water.
A wattmeter measures electrical power, whereas a voltmeter measures voltage, or potential difference.