Power Converter
Welcome to the comprehensive power converter designed for converting between watts, kilowatts, horsepower, BTU per hour, and all major power units. Perfect for electrical engineers, mechanical engineers, automotive professionals, HVAC technicians, and anyone working with power calculations and equipment specifications.
Universal Power Converter
Convert Any Power Unit Instantly
Select your units and enter a value to convert between all major power measurements.
Conversion Result
Quick Conversions
Common Power Conversions
1 Kilowatt
1 Horsepower
1 Kilowatt
1 Watt
Power Conversion Formulas
Watts to Kilowatts
\[ \text{Kilowatts} = \frac{\text{Watts}}{1,000} \]
Example: 5,000 W = 5,000 ÷ 1,000 = 5 kW
Horsepower to Watts
\[ \text{Watts} = \text{Horsepower} \times 745.7 \]
Example: 100 hp = 100 × 745.7 = 74,570 W
Power Definition
\[ P = \frac{E}{t} = \frac{\text{Energy}}{\text{Time}} \]
Power is the rate at which energy is transferred or work is done
Understanding Power Units
Watt (W)
The watt is the SI unit of power, named after Scottish engineer James Watt. One watt equals one joule per second. It measures the rate of energy transfer and is universally used for electrical power. A 60-watt light bulb consumes 60 joules of energy every second. The watt is fundamental in electrical engineering, electronics, and energy systems.
Kilowatt (kW)
A kilowatt equals 1,000 watts. It's the standard unit for measuring household electrical consumption and appliance power ratings. Air conditioners, heaters, and electric vehicles are typically rated in kilowatts. Your electricity bill measures consumption in kilowatt-hours (kWh), which is energy, not power.
Horsepower (hp)
Horsepower is a unit of power originally developed by James Watt to compare steam engine output to the power of draft horses. One mechanical horsepower equals approximately 745.7 watts. Commonly used for engines, motors, and mechanical systems. The automotive industry primarily uses horsepower to rate engine power output.
Metric Horsepower (PS)
Also called Pferdestärke (German for "horse strength"), metric horsepower equals approximately 735.5 watts. Slightly different from mechanical horsepower, it's used in Europe and Asia for vehicle ratings. One metric HP equals about 0.9863 mechanical horsepower.
BTU per Hour (BTU/h)
BTU per hour measures thermal power, commonly used for heating and cooling systems. One BTU/h equals approximately 0.293 watts. Air conditioners, furnaces, and heaters are rated in BTU/h. A 12,000 BTU/h air conditioner produces cooling power equivalent to about 3,517 watts or 3.5 kW.
Comprehensive Conversion Tables
Electrical Power Units
| Unit | Watts | Kilowatts | Horsepower |
|---|---|---|---|
| 1 Watt | 1 W | 0.001 kW | 0.00134 hp |
| 1 Kilowatt | 1,000 W | 1 kW | 1.341 hp |
| 1 Megawatt | 1,000,000 W | 1,000 kW | 1,341 hp |
| 1 Gigawatt | 1×10⁹ W | 1,000,000 kW | 1.341×10⁶ hp |
Mechanical Power Units
| Unit | Watts | Horsepower | Metric HP |
|---|---|---|---|
| 1 Horsepower (mech) | 745.7 W | 1 hp | 1.014 PS |
| 1 Metric Horsepower | 735.5 W | 0.9863 hp | 1 PS |
| 1 Foot-Pound/Second | 1.356 W | 0.00182 hp | 0.00184 PS |
| 100 Horsepower | 74,570 W | 100 hp | 101.4 PS |
Thermal Power Units
| Unit | Watts | BTU/Hour | kW |
|---|---|---|---|
| 1 BTU/Hour | 0.293 W | 1 BTU/h | 0.000293 kW |
| 1,000 BTU/Hour | 293 W | 1,000 BTU/h | 0.293 kW |
| 12,000 BTU/Hour | 3,517 W | 12,000 BTU/h | 3.517 kW |
| 1 BTU/Second | 1,055 W | 3,600 BTU/h | 1.055 kW |
Practical Conversion Examples
Example 1: Converting Engine Power
A car engine produces 150 horsepower. Convert to kilowatts.
\[ 150 \text{ hp} \times 745.7 = 111,855 \text{ W} = 111.9 \text{ kW} \]
Result: 150 hp = 111.9 kilowatts
Example 2: Air Conditioner Rating
An AC unit is rated at 24,000 BTU/hour. Convert to kilowatts.
\[ 24,000 \text{ BTU/h} \times 0.293 = 7,032 \text{ W} = 7.03 \text{ kW} \]
Result: 24,000 BTU/h = 7.03 kilowatts
Example 3: Household Appliance
A microwave oven uses 1,200 watts. Convert to horsepower.
\[ 1,200 \text{ W} \div 745.7 = 1.609 \text{ hp} \]
Result: 1,200 W = 1.61 horsepower
Applications of Power Conversion
- Automotive Engineering: Converting engine power between horsepower and kilowatts for international specifications
- HVAC Systems: Translating air conditioner ratings from BTU/h to kilowatts for energy calculations
- Electrical Engineering: Sizing generators, motors, and electrical systems using standard power units
- Renewable Energy: Calculating solar panel output, wind turbine capacity, hydroelectric generation
- Industrial Machinery: Specifying motor power requirements for manufacturing equipment
- Marine Engineering: Converting ship engine power for international vessel specifications
- Aviation: Aircraft engine power ratings and performance calculations
- Energy Auditing: Assessing power consumption and efficiency across different systems
Power Conversion Tips
- Power vs Energy: Power is rate (watts), energy is amount (watt-hours)—don't confuse them
- Mechanical vs Metric HP: Specify which horsepower type—they differ by about 1.4%
- Peak vs Continuous: Motors often have peak and continuous ratings—verify which applies
- Efficiency Losses: Real systems lose power to heat, friction, and resistance
- AC vs DC Power: Different calculation methods apply for alternating and direct current
- Three-Phase Systems: Industrial power calculations may require √3 factor
- Power Factor: In AC systems, apparent power differs from real power
Common Power Questions
How many watts in a horsepower?
One mechanical horsepower equals approximately 745.7 watts. This conversion was established by James Watt when comparing steam engine output to horse power. Metric horsepower (used in Europe) equals about 735.5 watts, slightly less than mechanical horsepower.
What's the difference between power and energy?
Power is the rate of energy transfer measured in watts (joules per second). Energy is the total amount of work done measured in watt-hours or joules. A 100-watt light bulb uses power at a rate of 100 watts; running for 10 hours consumes 1,000 watt-hours (1 kWh) of energy.
How do I convert BTU/hour to watts?
Multiply BTU per hour by 0.293071 to get watts. For example, 12,000 BTU/h × 0.293 = 3,516 watts or 3.5 kW. This conversion is essential for HVAC systems rated in BTU but requiring electrical power specifications in watts or kilowatts.
Why Choose RevisionTown for Conversion Tools?
RevisionTown specializes in creating accurate, user-friendly calculators and educational resources for students, professionals, and anyone working with technical calculations. Our power converter is designed by expert educators who understand both the mathematics and practical applications across multiple engineering disciplines.
Whether you're a student learning about power in IB, AP, GCSE, IGCSE curricula, an engineer specifying equipment, an automotive professional comparing engine outputs, or anyone needing accurate power conversions, our calculator provides instant results with clear explanations.
Our commitment to educational excellence extends beyond simple conversion—we provide context, formulas, comprehensive tables, and practical understanding. The power converter exemplifies our approach: support for all major power units including electrical, mechanical, and thermal measurements, clear mathematical formulas, extensive reference tables covering automotive, HVAC, and industrial applications, and tools that serve genuine needs in engineering, education, and professional work.
Disclaimer: This power converter is provided for educational and general purposes. While we strive for maximum accuracy using internationally standardized conversion factors, results should be verified for critical applications such as engineering design, equipment specification, or safety-critical systems. Different power definitions exist for some units (mechanical vs metric horsepower). For professional engineering, electrical, or safety-critical applications, consult authoritative references and verify all conversions. Conversion factors used: 1 hp (mech) = 745.69987 W exactly, 1 metric hp = 735.49875 W, 1 BTU/h = 0.29307107 W.
