Unit Converters
Power Converter
Convert power units: watts, kilowatts, horsepower, BTU/hr, calories/second, and more. Perfect for engineering, automotive, electrical, and HVAC applications.
Use Power Converter to get instant results without uploads or sign-ups. Everything runs securely in your browser for fast, reliable output.
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About this tool
Power conversion is essential in engineering, automotive, electrical, and HVAC fields. Power measures the rate of energy transfer or work done per unit time. Different industries use different power units: electrical engineering uses watts and kilowatts, automotive uses horsepower, HVAC uses BTU/hr (British Thermal Units per hour), and physics may use various combinations. Understanding power conversions helps compare equipment capabilities and energy consumption rates.
Our Power Converter handles all common power units with precision. Convert between SI units (watts, kilowatts, megawatts), mechanical units (horsepower in various standards), thermal units (BTU/hr, tons of refrigeration), and other specialized units. The calculator uses exact conversion factors ensuring accuracy for engineering specifications, equipment selection, and system design.
Power conversions are crucial in many applications: comparing electric motors, sizing HVAC systems, understanding vehicle engine output, calculating electrical loads, comparing appliance energy consumption rates, and evaluating renewable energy systems. For example, a typical household microwave uses about 1,000 watts (1 kW), while a car engine might produce 150-300 horsepower.
The converter is valuable for mechanical engineers designing power transmission systems, electrical engineers sizing circuits and generators, HVAC technicians selecting equipment, automotive enthusiasts comparing vehicle performance, and homeowners understanding appliance power requirements. Accurate power conversions ensure proper equipment selection, prevent system overloads, and enable meaningful comparisons across different technologies.
Usage examples
Car Engine
Convert 200 horsepower to kilowatts
200 HP = 149.14 kW
Air Conditioner
Convert 12,000 BTU/hr cooling to watts
12,000 BTU/hr = 3,517 W
Electric Motor
Convert 5 kW motor to horsepower
5 kW = 6.71 HP
Small Appliance
Convert 1,500 watts to BTU/hr
1,500 W = 5,119 BTU/hr
Industrial Equipment
Convert 100 HP to megawatts
100 HP = 0.0746 MW
How to use
- Enter the power value you want to convert.
- Select the unit you're converting FROM (e.g., watts).
- Select the unit you're converting TO (e.g., horsepower).
- Click "Convert" to see the result instantly.
- The converter shows precise results for engineering calculations.
- Useful for motor specifications, HVAC sizing, and electrical system design.
Benefits
- Convert between all common power units instantly
- Accurate conversions using international standards
- Essential for electrical system design and sizing
- Useful for comparing motor and engine specifications
- Helps size HVAC equipment correctly
- Perfect for automotive power comparisons
- Simplifies appliance energy consumption understanding
- Educational tool for engineering students
- Free alternative to manual conversion calculations
- Prevents equipment sizing errors
- Mobile-friendly for field use
- Supports both mechanical and electrical power units
FAQs
How many watts are in one horsepower?
One mechanical horsepower (HP) equals approximately 745.7 watts or 0.7457 kilowatts. This is based on the definition that 1 HP = 550 foot-pounds per second. There are different horsepower standards: mechanical (745.7 W), metric (735.5 W), and electrical (746 W), but mechanical HP is most common in the US.
What is the difference between power and energy?
Power is the rate of energy transfer (energy per unit time), measured in watts. Energy is the total amount transferred, measured in joules or watt-hours. A 100-watt light bulb uses power at a rate of 100 W; running it for 10 hours consumes 1,000 watt-hours (1 kWh) of energy. Power is instantaneous; energy accumulates over time.
How do I convert BTU/hr to watts for HVAC?
Multiply BTU/hr by 0.293071 to get watts. For example, a 12,000 BTU/hr air conditioner equals about 3,517 watts (3.517 kW). HVAC equipment is often rated in BTU/hr in the US, while electrical power is in watts, so conversion is necessary for circuit sizing and energy calculations.
Why do car engines use horsepower instead of watts?
Horsepower has historical roots in the automotive industry, dating back to when steam engines were compared to horse-drawn carriages. While watts are the SI unit, horsepower remains traditional in automotive contexts, especially in the US. However, many countries now also specify engine power in kilowatts (kW).
What is a ton of refrigeration?
A ton of refrigeration is 12,000 BTU/hr, or about 3,517 watts (3.517 kW). It represents the cooling power needed to freeze one ton (2,000 lbs) of water in 24 hours. HVAC systems are often sized in tons: a 3-ton AC unit provides 36,000 BTU/hr or about 10.5 kW of cooling.
How much power does a typical home use?
Average US homes use about 1.2 kW continuously (30 kWh per day ÷ 24 hours), but peak usage can reach 5-10 kW when multiple appliances run simultaneously. Large appliances: air conditioner (2-5 kW), electric stove (2-3 kW), water heater (3-4 kW), microwave (1 kW). Circuit breakers are sized for peak loads.
Can I use this to compare electric vs gas engines?
Yes! Electric motors are often rated in kW while gas engines use HP. Convert both to the same unit for comparison. However, note that electric motors typically deliver peak power instantly while gas engines have power curves. Also consider that electric motors are generally more efficient at converting energy to mechanical work.
What is kilowatt-hour vs kilowatt?
Kilowatt (kW) is power - the rate of energy use. Kilowatt-hour (kWh) is energy - the total amount used. A 1 kW appliance running for 1 hour uses 1 kWh of energy. Your electric bill charges for kWh (energy consumed), not kW (instantaneous power). Running a 2 kW heater for 5 hours uses 10 kWh.
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