Watt vs. Kilowatt: What’s the Difference?

amps vs. watts

Watt vs. Kilowatt: What’s the Difference?

Watt and kilowatt are common measurement units in the electrical engineering field. The two units measure the rate of electricity flow at a particular duration. However, many people confuse these measuring units when undertaking electrical projects. So, what is the difference between watt vs. kilowatt? When is each unit used? Here is a comparison framework between the two to help clear this confusion.

Watt vs. Kilowatt: Side-By-Side Comparison

InventorJames Watt James P. Joule
International System of Units DesignationUnit of PowerUnit of Power
Formula1 Joule per second;
Amps x Volts
Power in watts/1000
Equivalency0.001 kilowatts1000 watts

Watt vs. Kilowatt: What’s the Difference?

The most straightforward answer: 1000 watts equals 1 kilowatt. A watt measures the power production or consumption rate at a given moment. Kilowatt measures the same rate of electrical flow over time for larger electrical devices like electric showers. Let’s dig deeper into the differences




As a unit of Power, a watt is equal to one joule of work per second. This is the amount of energy transfer that is required to perform work, or the amount of energy in Joules that an electrical device uses per second while running. When thinking about measuring electricity, a watt is equal to the amount of current in amps multiplied by the amount of potential in volts. Essentially, a watt measures power consumption.

Currently, we commonly use watt as the smallest energy unit. Appliance manufacturers use watts as power descriptors on devices or machines such as microwaves, light bulbs, Televisions, and dishwashers. Thus, the indicated watts on any appliance represent the power quantity that the gadget transfers or consumes within a moment. For instance, a 60W light bulb consumes 60 watts per second.  

When scaling up the power units, 1,000 watts equals 1 kilowatt, 1,000,000 watts amounts to 1 megawatt, and 1,000,000,000 watts make 1 gigawatt.

amps vs. watts
A 60W light bulb consumes 60 watts of energy every second it is on.



Similarly, a kilowatt measures the electrical power of a device. It provides a more accurate measure and describes the strength of an appliance. It’s important to note that the unit of energy base measurements on watts as 1 kilowatt equals 1,000 watts. However, a kilowatt is used in most electrical appliances, especially where the volume of electricity consumed by the specific gadget is large. That explains why the electrical energy of a light bulb is expressed in watts while that of an array of 30 solar panels is in kilowatts.

In other words, a kilowatt is more fitting when used as a unit of measure on appliances like air conditioners, refrigerators, heaters, and engines, to mention a few. Kilowatt is also used in broadcasting engineering to express electromagnetic energy from TV and radio transmitters. You can convert watts and kilowatts into larger power measurement units such as megawatts or gigawatts.

Other Units


A megawatt is equivalent to 1,000,000 watts and 1,000 kilowatts. Megawatts measure the power capacity of a power plant in a relatively large area like a city. A megawatt-hour refers to the power consumed every hour in megawatts. It is what you need to power two refrigerators running throughout the year, a 3,600 miles driven EV, and two 0.06 kW light bulbs running continuously for 12 months.   


Gigawatts measure the electrical power of various power plants. A gigawatt is equivalent to 1 billion watts and 1,000 megawatts. This power quantity powers 10 million 100W light bulbs, 100 million LED lights, around 9,000 electric vehicles, and more than 750,000 households.


The watt power unit derived its name from Scottish physicist James Watt. The scientist used this unit to measure the power output of his steam engines. In 1882, C. William Siemens suggested it  (watt)) be used as a power unit. He defined it as the energy a current transfers through the volt potential differences. The power unit became an international system of units in 1960.

Eight years later, James Prescott Joule coined the term kilowatt in 1890. The English physicist used the kilowatts unit to measure the light bulb’s electrical energy. Over the years, the units have interchanged their usage. Watts now measure low power output, such as light bulbs, while heavy machines like heaters, lawn mowers, and electric vehicles use kilowatts as their power unit.

hart 40v vs ryobi 80v mower
A typical electric push lawn mower will use between 2-4kW to recharge.

©Virrage Images/Shutterstock.com


A multimeter measures the volts and amps in a DC circuit using the following standard formulas:

You measure Power in watts by multiplying amps times volts:

watts = amps x volts  

For example, if an electric current has 100 volts and 8 amps, then its watts will be:

watts = 100 x 8

           = 800W

In contrast, we divide power in watts by 1,000 to calculate electricity flow in kilowatts as follows:

1kW = 1000W

Power in kilowatts = Power in watts/1,000 or P(kW) = P(W)/1,000

For instance, if a light bulb has 60W, you will divide 60W by 1000 to get 0.06kW.

Power in kilowatts = 60/1000

                       = 0.06 kilowatts

Also, you can convert kilowatts into watts using the following formula:

Power in watts = 1,000 x Power in kilowatts or P(W) = 1,000 x P(kW)

For example, if we have a 0.06 kW light bulb, we should multiply it by 1000 when converting the units into watts.

Power in watts = 1000 x 0.06

                     = 60 watts

Watt vs. Kilowatt: 7 Must-Know Facts

  • Both watt and kilowatt are power units describing the work rate.
  • The two are the derived power units in the metric system.
  • One watt is equivalent to one joule of work per second.
  • Kilowatt expresses the energy and the rate an electric vehicle is charged.
  • Amps and volts are crucial when calculating watts.
  • Watts use the symbol W, while kilowatts use kW.
  • A wattmeter device is what you need to measure watts.

Watt vs. Kilowatt: Which One Is Better? Which One Should You Use?

The type of appliances will influence the power measurement units to use. Watt applies to appliances and projects that consume less power, like phone and laptop chargers and light bulbs. Conversely, kilowatts give accurate power rates for devices that consume large volumes of energy, such as electric mowers, ACs, and vehicles. One thousand watts equal 1 kilowatt. Thus, kilowatts are easy to calculate in large power outputs.

Frequently Asked Questions

Are watts similar to kilowatts?

A watt and kilowatt measure the electrical flow. However, a watt is a small unit of power. It measures small power quantity, whereas kilowatt measures larger power rates.

What are the average power usage rates per household?

The energy consumed in a household depends on the number of electrical devices connected to a power source and their usage. However, the average consumption ranges between 1.22-2.44 kilowatts per day.

Is watt important?

Watt as a power unit is significant to any household as it helps determine the electricity consumed for billing. In electrical engineering, watts aid in identifying the energy a machine requires to run.

What home appliances use watts as unit of measure?

Electrical devices at home can use either watts or kilowatts. Chargers and bulbs tend to consume low quantities of power and have watts as their power measuring unit.

Can I have a negative kilowatt reading?

Yes, you can have a negative kilowatt reading. Incorrect current transformer electrical polarity might lead to negative kilowatt readings.

What are the various forms of watts?

You can use kilowatts, megawatts, gigawatts, or terawatts to represent watts (i.e., one thousand watts equals one kilowatt, and one million watts equals one megawatt). The selected unit depends on the quantity of the power output.

What are the various types of measuring power?

Watts, kilowatts, megawatts, and gigawatts are different ways of measuring power. The electricity bill comes in kilowatt-hours.

Why measure power?

Power measuring aids in managing electricity consumption and increasing its efficiency.

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