Power Converter ⚡
Free online power unit converter. Convert watts, kilowatts, horsepower, BTU/hour, and 25+ power units instantly. Includes kW to HP, watts to horsepower calculator with formulas.
📐 Conversion Formula
Common Power Conversions
| From | To | Multiply by | Example |
|---|---|---|---|
| 1 kW | HP | 1.34102 | 75 kW = 100.58 HP |
| 1 HP | kW | 0.7457 | 100 HP = 74.57 kW |
| 1 W | HP | 0.001341 | 1000 W = 1.34 HP |
| 1 HP | W | 745.7 | 2 HP = 1491.4 W |
| 1 kW | W | 1,000 | 5 kW = 5,000 W |
| 1 W | BTU/h | 3.412 | 1000 W = 3412 BTU/h |
| 1 HP | BTU/h | 2544.43 | 1 HP = 2544.43 BTU/h |
| 1 kW | BTU/h | 3412.14 | 5 kW = 17,061 BTU/h |
Quick Power Conversions
kW to HP
× 1.34102
1 kW = 1.341 HP
HP to kW
× 0.7457
1 HP = 0.746 kW
W to HP
÷ 745.7
1000 W = 1.34 HP
W to BTU/h
× 3.412
1 W = 3.412 BTU/h
Converter Performance Metrics
How to Use Power Converter
Step 1: Enter Power Value
Type the power value you want to convert in the "From" field. The converter accepts any positive or negative number including decimals. For example, enter 75 for 75 kW or 100 for 100 horsepower depending on your selected unit.
Step 2: Select Source Unit
Choose the unit of your input power from the "From" dropdown. Options include watts, kilowatts, horsepower (various types), BTU/hour, joules/second, and 20+ other power units. Select the unit that matches your measurement.
Step 3: Select Target Unit
Pick the unit you want to convert to from the "To" dropdown. The conversion happens automatically in real-time as you change units. The formula used for conversion is displayed below the converter for reference.
Step 4: Use Results
View the converted result in the "To" field. Click Copy to copy the result to clipboard, Swap to reverse conversion direction, or Reset to start over. All calculations are instant and highly accurate for engineering applications.
Understanding Power Units
What is Power?
Power is the rate at which energy is transferred or work is performed per unit time. The SI unit is the watt (W), defined as one joule per second. Power is fundamental to electrical engineering, mechanical engineering, physics, and everyday applications from engines to light bulbs.
Formula: Power \( P = \frac{E}{t} \) where \( E \) is energy in joules and \( t \) is time in seconds. For mechanical power: \( P = F \times v \) where \( F \) is force and \( v \) is velocity. For electrical power: \( P = V \times I \) where \( V \) is voltage and \( I \) is current. One watt equals one joule per second.
Common Power Units Explained
Watt (W): SI unit of power named after James Watt. One watt is one joule per second. Common for electrical devices: light bulbs (60W), microwave ovens (1000W), phones (5-20W). Kilowatt (kW) = 1,000 watts. Megawatt (MW) = 1,000,000 watts.
Horsepower (HP): Imperial/US customary unit originally defined by James Watt comparing steam engines to draft horses. One mechanical horsepower = 745.7 watts. Variants: electric HP (746W), metric HP (735.5W), water HP (746.04W). Used for engines, motors, and machinery ratings.
BTU/hour: British Thermal Unit per hour. Common in HVAC, refrigeration, and heating systems. One BTU is heat required to raise one pound of water by 1°F. Conversion: 1 watt = 3.412 BTU/h. Air conditioners rated in BTU/h (typical home AC: 12,000-18,000 BTU/h).
Common Use Cases
🚗 Automotive Engineering
Convert engine power between horsepower and kilowatts for vehicle specifications. Different regions use different units—USA uses HP, Europe uses kW. Essential for comparing car performance, understanding power ratings, and technical specifications across international markets.
⚡ Electrical Engineering
Convert electrical power ratings for motors, generators, appliances, and circuits. Calculate power consumption, size electrical systems, specify transformers, and design power distribution networks. Essential for load calculations and energy management systems.
🌡️ HVAC Systems
Convert between watts, BTU/hour, and tons for air conditioning and heating equipment. Size HVAC systems correctly, compare unit efficiency, and calculate cooling/heating loads. Critical for energy-efficient building design and climate control system selection.
🏭 Industrial Equipment
Convert power ratings for pumps, compressors, conveyor systems, and machinery. Specify motors correctly, calculate energy costs, and ensure adequate power supply. Essential for plant design, equipment procurement, and operational efficiency optimization.
🌞 Renewable Energy
Convert solar panel output (watts), wind turbine ratings (kW/MW), and energy storage capacity. Calculate system sizing, compare renewable energy sources, and understand power generation capabilities. Essential for sustainable energy system design and evaluation.
🎓 Education & Science
Students and researchers convert power units for physics, engineering, and chemistry coursework. Understand energy transfer rates, calculate work done, and analyze system efficiency. Essential for lab experiments, homework problems, and understanding real-world applications.
Frequently Asked Questions
How do I convert kW to HP?
+To convert kilowatts (kW) to horsepower (HP), multiply by 1.34102. Formula: \( \text{HP} = \text{kW} \times 1.34102 \). Example: 75 kW × 1.34102 = 100.58 HP. This conversion is essential for automotive specifications—European cars show power in kW while American cars use HP. Both measure the same physical quantity but with different units.
How many watts are in 1 horsepower?
+One mechanical horsepower equals 745.7 watts. Formula: \( 1 \text{ HP} = 745.699872 \text{ W} \). Different HP types have slightly different values: electric HP = 746W, metric HP = 735.5W, water HP = 746.04W. For most applications, 746 watts is standard approximation. Originally defined by James Watt comparing steam engines to horses' work capacity.
How do I convert watts to BTU/hour?
+To convert watts to BTU per hour, multiply by 3.41214. Formula: \( \text{BTU/h} = \text{W} \times 3.41214 \). Example: 1,000W × 3.41214 = 3,412.14 BTU/h. Common in HVAC applications—air conditioners often rated in BTU/h while electrical consumption in watts. This conversion helps compare heating/cooling capacity with electrical power consumption.
What's the difference between watts and kilowatts?
+Kilowatt (kW) is 1,000 watts. Formula: \( 1 \text{ kW} = 1,000 \text{ W} \). Just a scaling factor—like kilometer vs meter. Small devices rated in watts (60W light bulb), larger equipment in kilowatts (5kW heater). Electricity bills show consumption in kilowatt-hours (kWh), which is energy not power. 1 kWh = using 1kW for one hour.
Why are there different types of horsepower?
+Different HP types evolved for specific applications. Mechanical HP (745.7W) is standard for engines and motors. Electric HP (746W) used for electric motors. Metric HP (735.5W) or PS used in Europe and Asia. Water HP for hydraulic power. Differences are small (1-2%) but matter for precise engineering. Always specify which type when citing HP ratings.
How do I convert HP to kW?
+To convert horsepower to kilowatts, multiply by 0.7457 (or divide by 1.34102). Formula: \( \text{kW} = \text{HP} \times 0.7457 \). Example: 100 HP × 0.7457 = 74.57 kW. Reverse of kW to HP conversion. Common when comparing American vehicles (HP) with European specifications (kW). More precise value: 0.745699872 for mechanical HP.