Power4all

Power Calculator

Calculate electrical power using voltage, current, and resistance with our advanced calculator
DC Power
AC Power
Applications

DC Power Calculator

Electrical Power Equations:
P = V × I   (Power = Voltage × Current) P = V² / R   (Power = Voltage squared divided by Resistance) P = I² × R   (Power = Current squared times Resistance)
12V
24V
120V
1A
5A
10Ω
Enter any two values to calculate power
0 W
0 W 250 W 500 W 750 W 1000+ W
Auto-calculate as you type

AC Power Calculator

AC Power Equations:
P = V × I × PF   (Real Power = Voltage × Current × Power Factor) S = V × I   (Apparent Power = Voltage × Current) Q = S × sin(φ)   (Reactive Power = Apparent Power × sin(phase angle))
120V
230V
5A
10A
PF 0.8
PF 0.95
Enter voltage and current to calculate AC power
0 W
0 W 500 W 1000 W 1500 W 2000+ W

Power Calculator Applications

Home Appliances

Calculate power consumption of household devices:

  • Refrigerator: 150-400W
  • Microwave: 600-1200W
  • Air Conditioner: 1000-4000W
  • LED Light Bulb: 7-20W

Example: A refrigerator drawing 2A at 120V consumes P = 120V × 2A = 240W

Industrial Applications

Power calculations for industrial equipment:

  • Electric Motors: Calculate power requirements based on load
  • Heating Elements: Design for specific power outputs
  • Power Distribution: Size cables and protection devices

Example: A 3-phase motor with line voltage 400V, current 12A, and power factor 0.85 consumes P = √3 × 400V × 12A × 0.85 = 7.06kW

Renewable Energy

Power calculations for renewable energy systems:

  • Solar Panels: Calculate expected power output
  • Wind Turbines: Determine power generation at different wind speeds
  • Battery Systems: Size energy storage requirements

Example: A solar panel with 20V output and 5A current produces P = 20V × 5A = 100W

Electronics Design

Power calculations for electronic circuits:

  • Component Selection: Choose components with appropriate power ratings
  • Heat Dissipation: Calculate thermal requirements
  • Battery Life: Estimate runtime based on power consumption

Example: A resistor with 10Ω resistance and 2A current dissipates P = I²R = 2²A × 10Ω = 40W

Understanding Power Equations

Electrical power (P) is the rate at which energy is used or produced in a circuit. It can be calculated using three equations depending on which quantities you know:

Example 1: Using P = V × I

An electric bulb operates at 220 V and draws a current of 0.5 A. What is the power consumption?

Solution: P = 220 × 0.5 = 110 W

Example 2: Using P = V² / R

A resistor has a resistance of 10 Ω and a voltage of 20 V across it. What is the power dissipated?

Solution: P = 20² / 10 = 400 / 10 = 40 W

Example 3: Using P = I² × R

A resistor has a resistance of 8 Ω and a current of 2 A flows through it. What is the power dissipated?

Solution: P = 2² × 8 = 4 × 8 = 32 W

Example 4: AC Power with Power Factor

An AC device operates at 230 V, draws 5 A, and has a power factor of 0.85. What is the real power?

Solution: P = 230 × 5 × 0.85 = 977.5 W