🎓 Physics • Electricity
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Electrical Power Calculator (P = VI)
Calculates electric power P = V × I = I²R = V²/R from voltage, current, or resistance.
Ohm’s Law & Electrical Power Calculator
Enter any 2 known values — the remaining 2 are solved instantly via V = IR and P = VI.
Standard Circuit Presets:
Unit: V
Unit: A
Unit: Ohms (Ω)
Unit: W (J/s)
Dynamic DC Circuit SchematicConventional Current Flow (Clockwise)
Voltage (V)
12 V
Current (I)
2 A
Resistance (R)
6 Ω
Power (P)
24 W
Step-by-Step Derivation
Given: Voltage V = 12 V, Current I = 2 A
1. Resistance: R = V / I = 12 / 2 = 6.0000 Ω
2. Power: P = V × I = 12 × 2 = 24.0000 W
What is Electrical Power?
Electrical power is the rate at which electrical energy is transferred by an electric circuit per second.
Formula & Step-by-Step Calculation
P = V × I = I²R = V² / R
Joule heating power relations.
Worked Step-by-Step Examples
Example 1
A 240 V heater drawing 10 A current
Solution: 2,400 Watts (2.4 kW)
• 240 × 10 = 2,400 W
Common Real-World & Academic Use Cases
- ✓ Electric utility consumption and power bills
- ✓ Solar panel watt peak sizing
- ✓ Power supply wattage ratings
How to Use the Electrical Power Calculator (P = VI)
1
Enter 2 Parameters
Input Voltage, Current, or Resistance.
2
Read Watts
Inspect power in Watts and Kilowatts.
Frequently Asked Questions
Q: What is 1 Kilowatt-hour (kWh)?
1 kWh is the energy consumed by a 1,000 Watt load running continuously for 1 hour (3.6 megajoules).