Electricity Calculator
Calculate power, energy, current, voltage, or resistance using various electrical formulas.
Calculate Electrical Values
Common Electricity Scenarios
Click on these links to see instant calculations with common values:
Understanding Electricity Calculations
Electricity involves fundamental concepts of voltage, current, resistance, power, and energy. These are interconnected through Ohm's Law and the power formula.
Formulas
V = I × R (Voltage = Current × Resistance)
I = V / R (Current = Voltage / Resistance)
R = V / I (Resistance = Voltage / Current)
Power Formulas:
P = V × I (Power = Voltage × Current)
P = I² × R (Power = Current² × Resistance)
P = V² / R (Power = Voltage² / Resistance)
Energy Formula:
Energy (kWh) = (Power in Watts × Hours) / 1000
Where:
• V = Voltage in Volts
• I = Current in Amperes
• R = Resistance in Ohms
• P = Power in Watts
• kWh = Energy in Kilowatt-hours
• Hours = Time duration in hours
Key Concepts
- Voltage (V): The electric potential difference.
- Current (A): The rate of flow of electric charge.
- Resistance (Ω): The opposition to the flow of electric current.
- Power (W): The rate at which energy is consumed or produced.
- Energy (kWh): The total amount of power consumed over a period of time.
Typical Electrical Values for Common Scenarios
| Scenario | Voltage (V) | Current (A) | Resistance (Ω) | Power (W) | Energy (kWh) (for 1 hr) |
|---|---|---|---|---|---|
| Small LED | 3 | 0.02 | 150 | 0.06 | 0.00006 |
| Phone Charger | 5 | 1 | 5 | 5 | 0.005 |
| Laptop | 19 | 3.42 | 5.55 | 65 | 0.065 |
| Microwave | 120 | 10 | 12 | 1200 | 1.2 |
| Electric Heater | 240 | 8.33 | 28.8 | 2000 | 2 |
Frequently Asked Questions
What is the difference between power and energy?
Power (Watts) is the rate at which energy is used or produced at a given moment. Energy (kWh) is the total amount of power consumed over a period of time. Think of power as speed and energy as distance traveled.
How are Ohm's Law and the Power Formula related?
Ohm's Law (V=IR) relates voltage, current, and resistance. The Power Formula (P=VI) relates power, voltage, and current. By combining these, you can derive formulas to find any unknown electrical quantity if you know at least two others.