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Horsepower vs. Kilowatts: What's the Difference?

Edited by Aimie Carlson || By Janet White || Published on January 6, 2024
Horsepower is a unit of power representing the force needed to move 550 pounds one foot in one second, while a kilowatt is a standard metric unit equal to 1,000 watts of electrical power.

Key Differences

Horsepower, a term coined by James Watt, measures the power of engines and motors, reflecting the power of horses. Kilowatts, part of the metric system, measure electrical power and are commonly used worldwide.
Horsepower quantifies the power output of engines, often in vehicles, using a traditional unit based on the capabilities of horses. Kilowatts, a metric unit, measure electrical power, central to electrical appliances and industrial machinery.
1 horsepower equals approximately 0.746 kilowatts. While horsepower is prevalent in automotive and mechanical contexts, kilowatts are more versatile, used in electricity generation and consumption.
Horsepower is deeply rooted in automotive culture, symbolizing engine strength. Kilowatts, being more modern and metric, are key in discussions about electricity and energy efficiency.
As the world shifts towards electric vehicles and renewable energy, kilowatts are becoming more prominent, although horsepower remains a popular term in automotive industries.

Comparison Chart


Developed in the 18th century by James Watt
Metric unit, part of the International System of Units


Common in automotive and mechanical engineering
Predominantly used in electrical applications




1 hp ≈ 0.746 kW
1 kW = 1,000 watts

Cultural Impact

Strongly associated with vehicle performance
More associated with electrical energy and appliances

Horsepower and Kilowatts Definitions


Horsepower, a traditional power unit, is rooted in history.
Old steam engines were measured in terms of horsepower.


A metric unit for measuring electrical power.
Our new solar panels generate 5 kilowatts of power.


A unit measuring engine power.
This car has 300 horsepower, making it very powerful.


Used to measure the output of electrical devices.
The generator has a capacity of 10 kilowatts.


Reflects the power output of mechanical engines.
The new tractor's engine boasts 75 horsepower.


Kilowatts are integral in renewable energy discussions.
Wind turbines can produce several hundred kilowatts.


Horsepower indicates the capability of vehicles.
Racing cars often have horsepower in the high hundreds.


Kilowatts quantify electricity consumption and production.
This appliance uses 1.5 kilowatts per hour.


Used to compare the performance of different engines.
Comparing horsepower helps buyers choose the right car.


Essential for understanding energy efficiency.
Energy-efficient bulbs use fewer kilowatts.


Abbr. hp A unit of power in the US Customary System, equal to 745.7 watts or 33,000 foot-pounds per minute.


A unit of power equal to 1,000 watts.


The power exerted by a horse in pulling.


Plural of kilowatt


(Informal) Effective strength
Political horsepower.
Computer horsepower.


(uncountable) Power derived from the motion of a horse.


A nonmetric unit of power (symbol hp) with various definitions, for different applications. The most common of them is probably the mechanical horsepower, approximately equal to 745.7 watts.


A metric unit (symbol often PS from the German abbreviation), approximately equal to 735.5 watts.


(uncountable) Strength.
Political horsepower


A unit of power equal to 746 watts


Where is horsepower commonly used?

In automotive and mechanical engineering to describe engine power.

How is horsepower calculated?

It's calculated based on the force needed to move 550 pounds one foot in one second.

What is horsepower?

Horsepower is a unit of power measuring the performance of engines.

Why are kilowatts important in energy discussions?

They help gauge electrical energy efficiency and consumption.

How are kilowatts used in daily life?

In measuring electrical power consumption and generation.

Is horsepower more common than kilowatts in cars?

Yes, especially in traditional petrol and diesel engines.

What is a kilowatt?

A standard metric unit of power equal to 1,000 watts.

Why is horsepower still used today?

It remains popular in the automotive industry for its historical significance and familiarity.

What does one horsepower equal in kilowatts?

Approximately 0.746 kilowatts.

How did horsepower originate?

Invented by James Watt to compare steam engines to horse power.

Is horsepower relevant in modern electric engines?

It's used for comparison but is gradually being replaced by kilowatts.

Is horsepower used in non-automotive contexts?

Less commonly, but it can be used in any mechanical power context.

What role do kilowatts play in green energy?

They are crucial for measuring the output of renewable energy sources.

Can horsepower be a measure of efficiency?

Indirectly, as it relates to the power output versus input.

Can horsepower and kilowatts be directly converted?

Yes, using the conversion 1 hp ≈ 0.746 kW.

Are kilowatts used globally?

Yes, as part of the International System of Units.

Are kilowatts related to kilowatt-hours?

Yes, kilowatt-hours measure energy consumption over time.

What sectors predominantly use kilowatts?

Electrical, renewable energy, and household appliances.

Do electric vehicles use horsepower or kilowatts?

They often use kilowatts, but horsepower is also used for consumer familiarity.

How do kilowatts help in household energy planning?

They allow for precise calculation of energy usage and costs.
About Author
Written by
Janet White
Janet White has been an esteemed writer and blogger for Difference Wiki. Holding a Master's degree in Science and Medical Journalism from the prestigious Boston University, she has consistently demonstrated her expertise and passion for her field. When she's not immersed in her work, Janet relishes her time exercising, delving into a good book, and cherishing moments with friends and family.
Edited by
Aimie Carlson
Aimie Carlson, holding a master's degree in English literature, is a fervent English language enthusiast. She lends her writing talents to Difference Wiki, a prominent website that specializes in comparisons, offering readers insightful analyses that both captivate and inform.

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