Kilowatts to Horsepower Converter

Need to convert kilowatts to horsepower (kW to hp)? This guide walks you through everything you need to know—from key definitions to conversion formulas and a handy reference table for quick lookups.

What Is a Kilowatt?

A kilowatt (symbol: kW) is a metric unit of power in the International System of Units (SI), equivalent to 1,000 watts. One watt is defined as one joule per second. Kilowatts are widely used to express the power output of electric motors, heating systems, and appliances.

Historical Background

The unit “watt” was named after James Watt, a Scottish inventor whose work greatly advanced the steam engine. The term “kilowatt” was later proposed by Sir Charles William Siemens in 1882 and officially adopted in 1908. Today, kilowatts are standard in energy and power applications worldwide.

What Is Horsepower (Metric)?

Horsepower (symbol: hp) is a traditional unit of power. Metric horsepower, primarily used in Europe and Asia, is equivalent to approximately 735.5 watts, based on 75 kgf·m/s.

Here’s how it compares to other types of horsepower:

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

While slight differences depend on the type of horsepower, metric horsepower is typically used for vehicles and mechanical systems outside the U.S.

Origin of the Term

James Watt introduced the concept of horsepower in the 18th century to better communicate the value of his steam engines. While earlier references to horsepower exist (like those by Thomas Savery in 1702), Watt’s version gained popularity and helped define engine performance for generations.

Kilowatts to Horsepower (Metric) Conversion Formula

To convert kilowatts to horsepower (metric), multiply the kilowatt value by 1.3596216173.

• 1 kW = 1.3596216173 hp (metric)
• Formula: hp = kW × 1.3596216173

To convert horsepower (metric) back to kilowatts:

• 1 hp (metric) = 0.73549875 kW

Example: Convert 15 kW to hp (metric)

15 kW × 1.3596216173 = 20.3943242595 hp
So, 15 kilowatts is approximately 20.39 horsepower (metric).

Kilowatt to Horsepower Conversion Table

Kilowatt (kW)	Horsepower (metric)
0.01 kW	0.0135962162 hp
0.1 kW	0.1359621617 hp
1 kW	1.3596216173 hp
2 kW	2.7192432346 hp
3 kW	4.0788648519 hp
5 kW	6.7981080865 hp
10 kW	13.596216173 hp
20 kW	27.192432346 hp
50 kW	67.981080865 hp
100 kW	135.96216173 hp
1000 kW	1359.6216173 hp

When to Use kW vs Horsepower

Kilowatts are more commonly used in electrical systems, appliances, and international standards, while horsepower remains widely used in the automotive and mechanical industries, especially in the U.S. and U.K. For technical and scientific purposes, kilowatts are the preferred SI-compliant unit.

Read more guideline here:

• NIST – Power Conversion Units
• BIPM – SI Units Overview

Related Tools

• Horsepower to Kilowatts
• KW to PS