Convert HP to KW

Need to convert hp to kw (horsepower to kilowatts)? This guide provides a detailed overview of the metric hp to kw (horsepower to kilowatt) conversion process, complete with definitions, history, and a quick-reference table.

Horsepower (Metric)

Horsepower (symbol: hp) is a unit used to measure power — the rate at which work is done. Metric horsepower, primarily used in Europe and Asia, is equal to roughly 735.5 watts (based on 75 kgf·m/s). For comparison:

• Mechanical or imperial horsepower ≈ 745.7 watts
• Boiler horsepower = 9809.5 watts
• Electrical horsepower = 746 watts

Each of these varies slightly based on application, but metric horsepower is standardized for most automotive and engineering uses.

Historical Background

The concept of horsepower was introduced by James Watt in the 18th century to demonstrate how effective his steam engines were compared to draft horses. Although earlier references to “horsepower” existed (notably by Thomas Savery in 1702), Watt’s definition gained widespread adoption. Today, metric and imperial horsepower are standard units for motor and engine ratings in various industries.

Kilowatt

The kilowatt (symbol: kW) is an SI (International System of Units) measurement of power. One kilowatt equals 1,000 watts or 1,000 joules per second. It is widely used to express the power output of motors, appliances, heating systems, and more.

Origin and Use

The watt, and consequently the kilowatt, was named in honor of James Watt. Proposed as a standard unit by Sir Charles William Siemens in 1882, it became official in 1908. Today, kilowatts are essential in describing everything from household electricity consumption (in kWh) to the capacity of electric vehicles and industrial machines.

Horsepower (Metric) to Kilowatt Conversion Table

How to Convert Horsepower (Metric) to Kilowatt

To convert metric hp to kw (horsepower to kilowatts), multiply the horsepower value by 0.73549875.

• 1 hp (metric) = 0.73549875 kW
• Formula: kW = hp × 0.73549875

To convert kilowatts back to horsepower (metric):

• 1 kW = 1.3596216173 hp (metric)

Example: Convert 15 hp to kW

15 hp × 0.73549875 = 11.03248125 kW
Therefore, 15 horsepower is equivalent to approximately 11.03 kilowatts.

Read more guideline here:

• National Institute of Standards and Technology
• International Electrotechnical Commission

Related Tools

• Kilowatts to Horsepower
• KW to PS