HP to kW Calculator

Convert between horsepower and kilowatts instantly. Supports mechanical, metric, electrical, and boiler horsepower conversions.

HP to kW
kW to HP
HP
Enter the horsepower value to convert
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1 HP
10 HP
50 HP
100 HP
150 HP
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Conversion Result
100 Mechanical HP = 74.57 kW
Input Value
100 HP
Mechanical Horsepower hp
Converted Value
74.57 kW
Kilowatts (kW)
Equivalent Power in Different Units
74.57
Kilowatts (kW)
100.00
Mechanical HP
101.39
Metric PS
100.00
Electrical HP

Understanding Horsepower and Kilowatts

Horsepower (HP) and kilowatts (kW) are both units of power, which measure the rate at which work is done or energy is transferred. While horsepower is commonly used in the automotive and mechanical industries, kilowatts are the standard SI unit for power used in scientific and engineering applications worldwide.

Power Conversion Formulas:

1 Mechanical Horsepower (hp) = 0.745699872 Kilowatts (kW)

1 Metric Horsepower (PS) = 0.73549875 Kilowatts (kW)

1 Electrical Horsepower = 0.746 Kilowatts (kW)

1 Boiler Horsepower = 9.8095 Kilowatts (kW)

Types of Horsepower

Horsepower Type Definition Conversion to kW Common Usage
Mechanical HP hp Also called Imperial horsepower. Defined by James Watt as 33,000 ft-lbf/min 1 hp = 0.7457 kW Automotive (US/UK), industrial machinery
Metric HP PS Pferdestärke (PS), defined as 75 kgf-m/s 1 PS = 0.7355 kW European automobiles, DIN standards
Electrical HP hp(E) Used for electrical motors, defined as exactly 746 W 1 hp(E) = 0.746 kW Electric motors, generators
Boiler HP hp(S) Used for boiler power, defined as 34.5 lb/h of steam at 212°F 1 hp(S) = 9.8095 kW Boiler capacity, steam engines

Practical Applications

1

Automotive Industry: Car engine power is typically rated in horsepower (hp in US/UK, PS in Europe). Converting to kilowatts allows for standardized international comparisons and compliance with regulations.

2

Electrical Engineering: Electric motor ratings often use horsepower, while electrical systems are designed in kilowatts. Conversion is essential for system compatibility and efficiency calculations.

3

Industrial Machinery: Manufacturing equipment power requirements must be accurately converted between units for international specifications and energy consumption calculations.

Conversion Examples

Horsepower Kilowatts Application Example
1 hp (mechanical) 0.746 kW Small electric hand tool
5 hp 3.73 kW Lawn mower engine
50 hp 37.28 kW Small tractor
150 hp 111.85 kW Standard family car
300 hp 223.71 kW Sports car
500 hp 372.85 kW High-performance vehicle
1000 hp 745.70 kW Racing car or small aircraft
5000 hp 3,728.50 kW Locomotive engine

Calculator Features:

  • Converts between all major horsepower types and kilowatts
  • Real-time calculation with immediate results
  • Shows equivalent values in all power units for comparison
  • Includes practical examples and common conversion values
  • Mobile-friendly interface with responsive design

Frequently Asked Questions

Mechanical horsepower (hp) is the original unit defined by James Watt as 33,000 foot-pounds per minute. Metric horsepower (PS or Pferdestärke) is defined as 75 kilogram-force meters per second. One mechanical horsepower equals approximately 1.0139 metric horsepower. Mechanical HP is used in the US and UK, while metric HP is used in Europe.

Different types of horsepower were developed for specific applications and measurement systems. Mechanical horsepower was created for steam engines, metric horsepower for European automotive applications, electrical horsepower for electric motors, and boiler horsepower for steam generation equipment. Each type has a slightly different definition based on the context in which it's used.

The conversions use standard accepted values with precision appropriate for engineering and practical applications. Mechanical HP to kW uses 0.745699872, metric HP uses 0.73549875, electrical HP uses 0.746, and boiler HP uses 9.8095. These values are accurate to within 0.01% for most practical purposes.

Boiler horsepower is specifically used to rate the steam generation capacity of boilers. One boiler horsepower represents the ability to evaporate 34.5 pounds of water per hour at 212°F. This unit is primarily used in heating, power generation, and industrial process applications involving steam systems.

For a rough estimate when converting kW to mechanical HP, you can multiply by 1.34 (or divide by 0.75). For kW to metric HP, multiply by 1.36 (or divide by 0.735). These approximations are accurate to within 2% for most practical purposes and useful for quick mental calculations.