Power Converter
Convert between watts, horsepower, kilowatts, megawatts, gigawatts, milliwatts, BTU per hour, calories per second, and foot-pounds per second instantly.
How to use the power converter
Enter your power value in the "From Value" field and select the appropriate power unit from the dropdown menu. Choose your target unit in the "To Value" section, and the converted result will appear instantly. Use the swap button to quickly reverse the conversion direction. All calculations happen in your browser for complete privacy and instant results.
This converter handles all major power units used in electrical engineering, mechanical engineering, automotive applications, and energy systems. Whether you're comparing engine horsepower to electric motor power, calculating electrical consumption, or working with industrial equipment, this tool provides precise conversions based on international standards.
Power measurements are essential for understanding energy transfer rates, efficiency calculations, and system design. Understanding how to convert between different units helps ensure proper equipment selection, energy planning, and effective communication across different industries and regions that may use different power standards.
Understanding power measurements
Watts and the SI system
The watt is the SI unit for power, defined as one joule per second. Named after James Watt, the Scottish inventor who made significant improvements to the steam engine, the watt is the standard unit for power measurements in scientific and engineering applications worldwide. For larger quantities, kilowatts (kW), megawatts (MW), and gigawatts (GW) are commonly used to avoid large numbers. The International Bureau of Weights and Measures (BIPM)defines the watt as the official SI unit for power.
Horsepower and mechanical power
Horsepower is a unit of power originally created by James Watt to compare the power of steam engines to the work done by horses. One horsepower equals approximately 745.7 watts. This unit remains widely used in automotive applications, particularly in the United States, for rating engines and motors. Different types of horsepower exist, including mechanical horsepower, electrical horsepower, and metric horsepower, but our converter uses the most common mechanical horsepower definition.
Electrical power units
Kilowatts and megawatts are the standard units for electrical power generation and consumption. Household electricity consumption is typically measured in kilowatt-hours for energy, but the instantaneous power draw is measured in kilowatts. Industrial power plants, wind turbines, and solar farms are rated in megawatts or gigawatts. Understanding these units is essential for energy planning, electrical system design, and renewable energy calculations.
Thermal power units
BTU per hour is commonly used for heating and cooling systems, especially in the United States. One BTU per hour equals approximately 0.293 watts. This unit is essential for understanding air conditioner capacity, furnace output, and heat pump performance. When shopping for HVAC equipment, the BTU/h rating helps determine the appropriate size for your space, ensuring efficient heating and cooling.
Small-scale power measurements
Milliwatts are used for measuring very small power levels in electronics, telecommunications, and sensor applications. One milliwatt equals 0.001 watts, making it perfect for describing the power consumption of LED indicators, wireless communication devices, and low-power microcontrollers. Understanding milliwatts is crucial for battery-powered device design and energy efficiency optimization.
Mechanical work power
Foot-pounds per second and calories per second are used in mechanical and thermodynamic applications. One foot-pound per second equals approximately 1.356 watts, representing the power needed to move one pound-force through one foot per second. Calories per second are used in thermodynamics and heat transfer calculations, particularly when dealing with metabolic rates or chemical reaction power.
Power generation and distribution
Large-scale power generation is measured in megawatts and gigawatts. A typical coal power plant might generate 500-600 megawatts, while a nuclear power plant can produce 1,000+ megawatts (1 gigawatt). National power grids are measured in gigawatts to handle the massive electricity demand of modern societies. Understanding these large-scale power units is essential for energy policy, grid management, and renewable energy planning.
Power efficiency and conservation
Power measurements are fundamental to understanding energy efficiency. The relationship between power, energy, and time (Energy = Power × Time) helps calculate consumption patterns and identify opportunities for energy savings. Whether you're designing an efficient motor, selecting appliances for your home, or planning industrial processes, understanding power units and conversions is essential for making informed decisions about energy use and conservation.
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Frequently Asked Questions
How many watts are in one horsepower?
One horsepower equals approximately 745.7 watts. This conversion is essential for comparing engine power, electric motors, and mechanical power systems.
What is the difference between watts and kilowatts?
One kilowatt equals 1,000 watts. Kilowatts are commonly used for larger power measurements like household electricity consumption, industrial equipment, and electric vehicle charging.
How do I convert BTU per hour to watts?
To convert BTU per hour to watts, multiply by 0.293071. For example, 1,000 BTU/h equals approximately 293.071 watts. This conversion is commonly used for air conditioning and heating systems.
What is a gigawatt?
A gigawatt equals 1 billion watts (1,000 megawatts). This unit is used for large-scale power generation, such as nuclear power plants, major hydroelectric facilities, and national power grids.
How many watts are in a milliwatt?
One milliwatt equals 0.001 watts (1/1000 of a watt). Milliwatts are commonly used for small electronic devices, sensors, and low-power applications like LED indicators and wireless communication devices.