Ohm's Law Calculator
Calculate voltage, current, resistance, and power using Ohm's Law with unit conversions and visual circuit relationships
Ohm's Law Calculator
Ohm's Law Relationships
V = I × R
P = V × I
I = V / R
R = V / I
Results
Consider component power ratings
12
Voltage (V)
2
Current (A)
6
Resistance (Ω)
24
Power (W)
Voltage
mV:12,000
V:12
kV:0.012
Current
μA:2.000e+6
mA:2,000
A:2
kA:0.002
Resistance
mΩ:6,000
Ω:6
kΩ:0.006
MΩ:6.000e-6
Power
μW:2.400e+7
mW:24,000
W:24
kW:0.024
MW:2.400e-5
Ohm's Law Wheel
Cover the unknown value to see the formula
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What is Ohm's Law Calculator?
Ohm's Law is a fundamental principle in electrical engineering that describes the relationship between voltage, current, resistance, and power in electrical circuits. This calculator helps you find any unknown electrical parameter when you know at least two others.
Ohm's Law Formulas
V = I × R (Voltage = Current × Resistance)
I = V / R (Current = Voltage / Resistance)
R = V / I (Resistance = Voltage / Current)
P = V × I (Power = Voltage × Current)
P = I² × R (Power = Current² × Resistance)
P = V² / R (Power = Voltage² / Resistance)
Understanding the Parameters
Voltage (V): The electrical potential difference, measured in volts. Think of it as electrical pressure.
Current (I): The flow of electrical charge, measured in amperes (amps). Think of it as the amount of electricity flowing.
Resistance (R): The opposition to current flow, measured in ohms (Ω). Think of it as electrical friction.
Power (P): The rate of energy consumption or production, measured in watts. Think of it as how much work electricity does.
Practical Applications
- Designing electrical circuits and selecting appropriate components
- Calculating power consumption and energy costs
- Determining safe current limits for wires and components
- Troubleshooting electrical problems in circuits
- Sizing power supplies and batteries for electronic projects
- Understanding LED driver requirements and resistor calculations
Safety Considerations
- Always ensure components can handle calculated power dissipation
- Use proper wire gauge for calculated current to prevent overheating
- Consider safety margins - don't operate components at maximum ratings
- High voltage and high current can be dangerous - follow safety protocols
- Heat dissipation becomes critical with higher power calculations
FAQ - Ohm's Law Calculator
Select what you want to calculate (voltage, current, resistance, or power), then enter any two known values. The calculator will compute all other values automatically using Ohm's Law relationships.