Meaning & use
watt
Last updated
Meaning
nouncountable
A unit of power equal to one joule per second, used to measure electricity and other forms of energy.
Grammar: Countable noun; often used with numbers, e.g., 'a 60-watt bulb'.
Patterns
- a 100-watt bulb
- watts of power
- consume watts
This light bulb uses only 10 watts of electricity.
The amplifier can deliver 50 watts per channel.
A typical microwave oven draws about 1000 watts.
Word forms
| plural | watts |
|---|
Common combinations
- watt-hour
- The battery has a capacity of 5000 watt-hours.
- 100-watt bulb
- Replace the 60-watt bulb with a 100-watt bulb for more light.
- watts of power
- The speaker produces 200 watts of power.
- per watt
- Solar panels are now cheaper per watt than ever before.
Synonyms and how they differ
- joule per second
- The scientific definition of a watt; 'watt' is the everyday unit name.
Word family
- wattage noun
- The amount of power in watts that a device uses or produces.
- kilowatt noun
- A unit equal to 1000 watts.
Commonly confused: watt or volt? watt or amp?
watt vs volt
A volt measures electrical potential difference, while a watt measures power. They are related but not the same.
watt vs amp
An amp measures electric current, not power. Power in watts equals volts times amps.
Practice
Choose the correct sentence:
Choose one answer.
Power is measured in watts, so '60 watts of power' is correct. Volts measure potential difference, amps measure current, and ohms measure resistance.
Make it your own
Write a sentence using “watt”, then check it and compare it with the examples above.