Common Power Conversions
About Power Conversion
Convert between different units of power including watts, horsepower, BTU per hour, and more. Essential for electrical engineering, mechanical engineering, and energy calculations.
Frequently Asked Questions
What is the relationship between horsepower and watts?
1 mechanical horsepower equals 745.7 watts, while 1 metric horsepower equals 735.5 watts. Horsepower was originally defined as the power of a draft horse, but watts are now the standard SI unit for power.
How much power do common household appliances use?
Typical power consumption: LED bulb (10W), microwave (1000W), refrigerator (150W), air conditioner (3000W), electric car charger (7000W). Understanding these helps estimate electricity costs and circuit requirements.
What's the difference between mechanical and electrical power?
Mechanical power involves physical motion (engines, motors), while electrical power involves current and voltage (P = V × I). Both are measured in watts, but conversion between them involves efficiency losses.
How do I calculate power consumption costs?
Cost = Power (kW) × Time (hours) × Rate ($/kWh). For example, a 1500W heater running 8 hours at $0.12/kWh costs: 1.5 × 8 × 0.12 = $1.44 per day.
What is power factor and why does it matter?
Power factor is the ratio of real power to apparent power in AC circuits. Poor power factor (below 0.9) wastes energy and can result in utility penalties for large commercial users.
How powerful are electric vehicle motors?
EV motors typically range from 100-400 kW (134-536 HP). They're more efficient than gasoline engines (90% vs 30%) and provide instant torque, explaining their superior acceleration performance.