Power Converter
Convert between watts, horsepower, BTU/h, and other power units with precision. Perfect for electrical, mechanical, and HVAC applications.
Enter a power value to see conversions
Understanding Power Measurement Systems
SI Units (International System)
The watt (W) is the standard SI unit of power, defined as one joule per second. Used globally in scientific and engineering applications.
- • Watt (W) - Base unit (1 J/s)
- • Kilowatt (kW) - 1,000 watts (household appliances)
- • Megawatt (MW) - 1,000,000 watts (power plants)
- • Gigawatt (GW) - 1,000,000,000 watts (national grids)
- • Terawatt (TW) - 1,000,000,000,000 watts (global consumption)
Horsepower Systems
Different types of horsepower for various applications, each with specific conversion factors.
- • Mechanical HP - 745.7 watts (US automotive standard)
- • Metric HP (PS) - 735.5 watts (European automotive)
- • Electric HP - 746 watts (electrical motor rating)
- • Water HP - 746.043 watts (hydraulic systems)
- • Boiler HP - 9,809.5 watts (steam generation)
Essential Conversion Factors
Common Mechanical Conversions
- • 1 hp = 745.7 watts
- • 1 kW = 1.341 hp
- • 1 PS = 735.5 watts
- • 1 ft⋅lbf/s = 1.356 watts
- • 1 Boiler HP = 9.81 kW
Thermal Power Conversions
- • 1 BTU/h = 0.293 watts
- • 1 BTU/s = 1,055 watts
- • 1 cal/s = 4.184 watts
- • 1 kcal/h = 1.163 watts
- • 1 Ton Refrigeration = 3.517 kW
Electrical Power Conversions
- • 1 VA = 1 watt (resistive load)
- • 1 kVA = 1,000 watts (apparent)
- • Power = Voltage × Current
- • Real Power = VA × Power Factor
- • 1 J/s = 1 watt (definition)
Professional Applications
Electrical Engineering
- • Motor Sizing: Converting between HP and kW for motor specifications
- • Load Calculations: Determining electrical system requirements
- • Energy Efficiency: Comparing power consumption across systems
- • Grid Planning: MW and GW calculations for power distribution
- • Renewable Energy: Solar panel and wind turbine power ratings
Automotive Industry
- • Engine Performance: HP to kW conversions for specifications
- • Electric Vehicles: Motor power ratings and charging systems
- • Fuel Efficiency: Power-to-weight ratio calculations
- • Emissions Testing: Power output standardization
- • Racing Applications: Precise power measurements
HVAC Systems
- • Cooling Capacity: Tons of refrigeration to kW
- • Heating Systems: BTU/h to watts for sizing
- • Energy Audits: Power consumption analysis
- • System Design: Load calculations and equipment selection
- • Efficiency Ratings: Comparing different HVAC technologies
Industrial Applications
- • Manufacturing: Machine power requirements and energy costs
- • Process Engineering: Steam and thermal power calculations
- • Facility Management: Total power consumption monitoring
- • Equipment Specification: Motor and drive sizing
- • Energy Management: Peak demand and load balancing
Power Measurement Best Practices
Measurement Accuracy
- • Use appropriate instruments for power range
- • Consider power factor in AC measurements
- • Account for temperature effects on equipment
- • Calibrate instruments regularly
- • Document measurement conditions
Safety Considerations
- • Follow lockout/tagout procedures
- • Use proper PPE for electrical work
- • Verify equipment ratings before connection
- • Consider arc flash hazards
- • Ensure proper grounding
Power Examples by Category
Household Appliances
- • LED Bulb: 5-15 W
- • Smartphone Charger: 5-20 W
- • Laptop: 45-90 W
- • Microwave: 700-1200 W
- • Hair Dryer: 1000-1800 W
- • Electric Kettle: 1500-3000 W
- • Air Conditioner: 1000-5000 W
Transportation
- • Bicycle (Human): 100-400 W
- • Motorcycle: 10-200 HP
- • Car Engine: 100-800 HP
- • Truck Engine: 200-600 HP
- • Ship Engine: 1000-100,000 HP
- • Jet Engine: 10,000-100,000 HP
- • Electric Car Motor: 50-1000 HP
Industrial & Power Generation
- • Wind Turbine: 1-15 MW
- • Solar Panel: 250-400 W each
- • Diesel Generator: 10 kW - 10 MW
- • Gas Turbine: 1-500 MW
- • Coal Power Plant: 500-1500 MW
- • Nuclear Reactor: 1000-1600 MW
- • Hydroelectric Dam: 100-22,500 MW
What's the difference between horsepower types?
Mechanical horsepower (745.7W) is used for engines and motors in the US. Metric horsepower (735.5W) is used in Europe for automotive ratings. Electric horsepower (746W) is used for electrical motor ratings. The differences are small but important for precise calculations.
How do I convert between electrical VA and watts?
Volt-Amperes (VA) represent apparent power, while watts represent real power. For DC circuits or purely resistive AC loads, VA = watts. For AC circuits with reactive components, watts = VA × power factor. This converter assumes a power factor of 1 for simplicity.
What's a ton of refrigeration?
A ton of refrigeration equals 12,000 BTU/hour or about 3,517 watts. It represents the cooling power needed to freeze one ton of water in 24 hours. It's commonly used to rate air conditioning systems - a 3-ton AC unit can cool about 3,517 × 3 = 10,551 watts of heat.
How accurate are these power conversions?
These conversions use internationally accepted conversion factors and are accurate to 6 decimal places. For most practical applications, this precision is more than sufficient. However, for critical engineering calculations, always verify with official standards and consider environmental factors.
Why are there different BTU/time units?
BTU per hour (BTU/h) is most common for HVAC systems, BTU per minute for higher-power heating applications, and BTU per second for industrial processes. The time unit significantly affects the power value: 1 BTU/s = 60 BTU/min = 3,600 BTU/h.