Ohm's Law Power Calculator
Calculate electrical power, voltage, current, and resistance using Ohm's law formulas
Ohm's Law Power Calculations
Electrical potential difference in volts
Electric current in amperes
Calculation Results
Example Calculations
Ohm's Law Power Formulas
Power Calculations
P = V × I (Power = Voltage × Current)
P = V²/R (Power = Voltage² ÷ Resistance)
P = R × I² (Power = Resistance × Current²)
Basic Ohm's Law
V = I × R (Voltage = Current × Resistance)
I = V/R (Current = Voltage ÷ Resistance)
R = V/I (Resistance = Voltage ÷ Current)
Electrical Units
Voltage (V)
Electrical potential difference measured in volts
Current (A)
Electric current measured in amperes
Resistance (Ω)
Electrical resistance measured in ohms
Power (W)
Electrical power measured in watts
Electrical Safety Tips
Always ensure power is off before working on circuits
Use proper PPE when working with electrical systems
Verify calculations before implementing in real circuits
Consider power ratings when selecting components
Understanding Ohm's Law and Electrical Power
What is Ohm's Law?
Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage across the two points and inversely proportional to the resistance between them. The fundamental relationship is V = I × R.
Electrical Power
Electrical power is the rate at which electrical energy is transferred by an electric circuit. It represents how fast electrical energy is converted to another form of energy such as heat, light, or mechanical energy.
Why is Power Important?
- •Determines energy consumption and electricity costs
- •Critical for component selection and circuit design
- •Helps prevent component overheating and failure
- •Essential for electrical safety calculations
Power Formula Applications
P = V × I
Most direct formula when voltage and current are known. Commonly used in AC/DC circuit analysis.
P = V²/R
Useful when voltage and resistance are known. Often used in resistive load calculations.
P = R × I²
Applied when current and resistance are known. Important for power dissipation calculations.
Remember: These formulas apply to resistive circuits. For AC circuits with reactive components, additional considerations are needed.
Real-World Applications
Household Appliances
A 1500W space heater on 120V draws 12.5A current.
I = P/V = 1500W ÷ 120V = 12.5A
LED Lighting
A 10W LED at 12V has 14.4Ω resistance.
R = V²/P = 144V² ÷ 10W = 14.4Ω
Automotive
Car headlight: 55W at 12V draws 4.58A.
I = P/V = 55W ÷ 12V = 4.58A