Power Converter

Convert Power Units Instantly with Our Free Power Converter Tool

Whether you’re an engineer designing electrical systems, an HVAC technician sizing equipment, or a student studying physics, converting between different power units is essential for accurate calculations. Our comprehensive power converter tool makes it easy to convert between watts, horsepower, BTU, and many other power units with precision and speed.

What is Power and Why Convert Between Units?

Power represents the rate at which energy is transferred or converted. Different industries and regions have developed their own preferred units for measuring power, which is why conversion tools are so valuable. Electrical engineers typically work with watts and kilowatts, automotive professionals use horsepower, and HVAC specialists often deal with BTU per hour.

Understanding these conversions helps you compare equipment specifications, verify calculations, and communicate effectively across different technical disciplines. For example, when selecting a generator for your home, you might need to convert your appliances’ wattage ratings to ensure the generator’s horsepower rating is sufficient.

How to Use the Power Converter

Using our power converter is straightforward and designed for both quick conversions and detailed analysis:

Step-by-Step Instructions

Enter Your Value: Input the power value you want to convert in the number field. The tool accepts decimal values for precise calculations.

Select Source Unit: Choose the unit of your input value from the dropdown menu. Options include watts, kilowatts, horsepower variants, BTU per hour, and specialized units like dBm.

View Results: The tool automatically displays conversions to all other supported units in real-time as you type, eliminating the need to click a convert button for most uses.

Copy or Note Results: All conversion results are clearly formatted and easy to read, making it simple to copy values for use in other calculations or documentation.

Supported Power Units

Our converter handles 14 different power units across multiple categories:

Electrical Units: Watts (W), Kilowatts (kW), Megawatts (MW), Milliwatts (mW), Microwatts (µW), and Decibel-Milliwatts (dBm)

Mechanical Units: Mechanical Horsepower, Electric Horsepower, and Metric Horsepower (PS)

Thermal Units: BTU per hour, BTU per second, Calories per second, and Tons of Refrigeration

Scientific Units: Joules per second (equivalent to watts)

Common Power Conversion Applications

Electrical and Electronics

Electrical professionals frequently convert between watts, kilowatts, and milliwatts when designing circuits, selecting components, or calculating energy consumption. For instance, a smartphone charger rated at 18 watts equals 18,000 milliwatts, which is useful when comparing with battery specifications often listed in milliwatt-hours.

Circuit designers working with RF equipment regularly convert between watts and dBm. A WiFi router transmitting at 20 dBm outputs approximately 100 milliwatts, information crucial for regulatory compliance and range calculations.

Automotive and Mechanical Engineering

The automotive industry primarily uses horsepower ratings, but engineers often need to convert to watts or kilowatts for international specifications or electric vehicle applications. A typical family car engine producing 200 mechanical horsepower generates approximately 149 kilowatts.

Electric vehicle specifications increasingly use kilowatts, making conversions essential when comparing traditional and electric powertrains. Understanding that one horsepower roughly equals 746 watts helps bridge this gap.

HVAC and Building Systems

Heating, ventilation, and air conditioning professionals work extensively with BTU per hour ratings but must often convert to watts or kilowatts for electrical load calculations. A 12,000 BTU air conditioner consumes approximately 3,517 watts, or about 3.5 kilowatts of electrical power.

When sizing backup generators for HVAC systems, technicians convert between BTU heating capacity and electrical power requirements to ensure adequate generator sizing.

Solar and Renewable Energy

Solar panel specifications use watts and kilowatts, but installers must understand how this translates to heating equivalents when replacing traditional heating systems. A 5-kilowatt solar array produces energy equivalent to approximately 17,060 BTU per hour under peak conditions.

Wind turbine specifications similarly require conversions between mechanical power output and electrical generation capacity for proper system design and energy calculations.

Understanding Different Types of Horsepower

The term “horsepower” encompasses several variations, each with specific applications and slightly different conversion factors:

Mechanical Horsepower

Mechanical horsepower, equal to 745.7 watts, is the most common variant in North America. Originally defined by James Watt as 33,000 foot-pounds per minute, this unit remains standard for internal combustion engines and many industrial applications.

Electric Horsepower

Electric horsepower equals exactly 746 watts and is used specifically for electric motors and electrical machinery. This slight difference from mechanical horsepower reflects the more precise nature of electrical measurements.

Metric Horsepower

Metric horsepower (735.5 watts) is widely used in Europe and other metric countries. Often abbreviated as PS (Pferdestärke), CV (chevaux vapeur), or other regional designations, this unit is approximately 1.4% smaller than mechanical horsepower.

BTU Conversions and HVAC Applications

British Thermal Units (BTU) measure thermal energy, with BTU per hour representing thermal power. These conversions are particularly important in HVAC applications:

One BTU per hour equals approximately 0.293 watts, making it relatively easy to convert between thermal and electrical power ratings. This conversion helps when calculating electrical load requirements for heating and cooling equipment.

Air conditioner efficiency ratings often combine BTU cooling capacity with electrical power consumption in watts, making these conversions essential for energy efficiency calculations and operating cost estimates.

Advanced Conversion Considerations

dBm and Logarithmic Scales

The dBm unit uses a logarithmic scale with 1 milliwatt as the reference point. This makes dBm particularly useful for telecommunications and RF applications where signal levels vary across many orders of magnitude.

Converting between dBm and watts requires logarithmic calculations: dBm = 10 × log₁₀(watts/0.001). Our converter handles these complex calculations automatically, making RF power conversions accessible to all users.

Scientific and Research Applications

Research applications often require conversions between various power units depending on the measurement context. Joules per second equals watts by definition, but researchers might encounter calories per second in biological or chemical contexts.

Understanding these relationships helps researchers communicate findings across disciplines and validate experimental results using different measurement approaches.

Tips for Accurate Power Conversions

Consider Measurement Context

Always verify which type of horsepower or BTU measurement applies to your specific situation. Equipment specifications should clearly indicate whether they use mechanical, electric, or metric horsepower.

When working with international equipment, be particularly careful about horsepower variants, as European specifications typically use metric horsepower while North American equipment uses mechanical horsepower.

Account for Efficiency Factors

Remember that power conversions show theoretical equivalents, but real-world applications involve efficiency losses. An electric motor rated at 5 horsepower doesn’t consume exactly 3,730 watts due to efficiency considerations.

Heat pump and air conditioner ratings often specify both thermal capacity (BTU) and electrical consumption (watts) separately because the thermal output exceeds electrical input through refrigeration cycle efficiency.

Verify Conversion Accuracy

For critical applications, double-check conversions using multiple methods or references. Our converter uses industry-standard conversion factors, but always verify that the specific standards match your application requirements.

Professional engineering work often requires specific precision levels, so consider whether the conversion accuracy meets your project specifications.

Frequently Asked Questions

How accurate are the power conversions?

Our converter uses officially recognized conversion factors from international standards organizations. Conversions are accurate to six decimal places for most applications, with scientific notation used for very large or small values to maintain precision.

Can I convert between energy and power units?

No, energy and power are different physical quantities. Power measures the rate of energy transfer (watts), while energy measures the total amount of work done (joules or kilowatt-hours). Energy equals power multiplied by time.

Why are there different types of horsepower?

Different horsepower variants developed historically in various industries and countries. Mechanical horsepower originated from James Watt’s measurements of horse performance, while electric horsepower was standardized for electrical applications. Metric horsepower provides a convenient round number in metric units.

When should I use dBm instead of watts?

Use dBm for telecommunications, RF, and signal processing applications where power levels vary across many orders of magnitude. The logarithmic scale makes it easier to work with very small power levels common in radio communications.

How do I convert between AC and DC power?

Our converter shows power unit equivalents regardless of AC or DC context. However, AC power calculations may involve additional factors like power factor and apparent power that affect the relationship between voltage, current, and real power.

Can this tool help with electrical load calculations?

Yes, the converter helps determine electrical loads by converting equipment power ratings to consistent units. However, remember to account for factors like starting currents, power factor, and diversity factors in comprehensive electrical load calculations.

What’s the difference between BTU and BTU per hour?

BTU measures energy (like joules), while BTU per hour measures power (like watts). Air conditioner ratings typically use BTU per hour to indicate cooling capacity, though this is often shortened to just “BTU” in common usage.

How do I size a generator using these conversions?

Convert all your equipment power requirements to the same unit (usually watts or kilowatts), add them up with appropriate safety margins, then convert to the generator’s rating unit (often horsepower). Remember that motor starting loads may require additional capacity.

Professional Applications and Industry Standards

Engineering and Design

Professional engineers rely on accurate power conversions for system design, equipment selection, and regulatory compliance. Whether sizing electrical panels, selecting motors, or calculating energy requirements, consistent units prevent costly design errors.

Building codes and equipment standards often specify power requirements in different units, making conversion tools essential for compliance verification and documentation.

Educational and Training

Students and trainees in electrical, mechanical, and HVAC programs benefit from understanding power unit relationships. These conversions appear frequently in textbook problems, laboratory exercises, and certification examinations.

International Collaboration

Global engineering projects require seamless communication between teams using different unit systems. Power conversions enable effective collaboration between professionals familiar with different measurement standards.

This comprehensive understanding of power units and conversions enhances professional communication and reduces errors in international engineering projects.